SMITHSONIAN MISCELLANEOUS COLLECTIONS VOLUME 57, NUMBER 13 CAMBRIAN GEOLOGY AND PALEONTOLOGY II No. 13.—DIKELOCEPHALUS AND OTHER GENERA OF THE DlKELOCEPHALINyt (With Plates 60 to 70) BY CHARLES D. WALCOTT (Publication 2187) CITY OF WASHINGTON PUBLISHED BY THE SMITHSONIAN INSTITUTION APRIL 4, 1914 Z^t £oti (§a(iimoxe (preee BALTIMORE, MD., U. S. A. CAMBRIAN GEOLOGY AND PALEONTOLOGY II No. 13.—DIKELOCEPHALUS AND OTHER GENERA OF THE DIKELOCEPHALIN^ By CHARLES D. WALCOTT (With Plates 60 to 70) CONTENTS PAGE Introduction 346 Classification 347 Observations on the genera 348 Synonymic references 349 Stratigraphic position of the DikelocephaUnse 353 Table of Upper Cambrian formations 353 Table of pre-Ordovician formations 354 Jordan formation 355 Fauna 355 St. Lajivrence formation 355 Fauna 356 Franconia formation 357 Fauna 357 Fauna of Eau Claire formation 358 Stratigraphic range of the genera 358 Dikelocephaltis 359 Saukia 360 OsceoUa 362 Calz'inella 362 Conokephalina 362 Description of genera and species 363 Genus Dikelocephalus Owen 363 Dikelocephalus ? dalyi, new species (pi. 64, figs. 1-5) 367 Dikelocephalus hartti (Walcott) (p\. 63. figs. 1-7, ya) 368 Dikelocephalus ? limbatiis Hall (pi. 65, figs. 5-8) 369 Dikelocephalus niiniiesotensis Owen (pi. 60, figs. 1-8; pi. 61, figs. 1-3, 5-7 ; pl- 62, figs. 4-6 ; pi. 65, fig. i) 369 Dikelocephalus minnesotensis var. (pl. 61, fig. 4) 371 Dikelocephalus iexanus, new species (pl. 65, fig. 4) 372 Dikelocephalus " tribulis Walcott (pl. 63, figs. 8-10, loa).... 372 Dikelocephalus vanhornei, new species (pl. 62, figs. 1-3) 373 Dikelocephalus, species undetermined (footnote^) 391 Genus Saukia, new genus 373 Saukia coloradoensis, new species (text figs. 13-16) 376 Saukia crassimarginata (Whitfield) (pl. 61, fig. 8; pl. 65, figs. 9, 10 ; pl. 66, figs. 2-5, 5a) 377 Saukia fallax, new species (pl. 67, figs. 21, 21a, 22, 22a) 378 Saukia junia, new species (text fig. 17) 378 Saukia ?? leptcenarum (Wiman) 379 Smithsonian Miscellaneous Collections, Vol. 57, No. 13 - . 345 346 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. ^7 PAGE Saiikia leucosia, new species (pi. 67, figs. 14-170) 379 Saiikia lodcnsis (Whitfield) (pi. 65, figs. 1-3) 379 Saukia marica (Walcott) (pi. 64, figs. 6, 6a) 380 Saukia pepinensis (Owen) (pi. 67, figs. 1-130) 381 Saukia pyrcne, new species (pi. 67, figs. 18-20) 382 Saukia riistica, new species (text figs. 18, 19) 383 Saukia stosei, new species (pi. 69, figs. 3-5 ; pi. 70, figs. 12, 120) 384 Saukia zvardi, new species (pi. 69, figs, i, 2) 384 Genus Osceolia, new genus 385 Osceolia osceola (Hall) (pi. 67, figs. 4-10) 386 Genus Conokephalina Brogger 387 ConokepJialina misa (Hall) (pi. 68, figs. 1-3) 387 Genus Calvinclla, new genus 388 Calvinella newtonensis (Weller) (pi. 70, figs. 7-11, iia) .'89 Calvinella ocarkensis. new species (pi. 70, figs. 1-6) 389 Calvinella spiniger (Hall) (pi. 68, figs. 11-230) 390 Cali'incUa tciinisciilpta, new species (pi. 64, figs. 7, 7a) 391 ILLUSTRATIONS Plate 60. Dikelocephahis ininnesotensis 392 61. Dikelocephahis ininnesotensis, Dikelocephahis niinnesotensis var. and Saukia crassimarginata 394 62. Dikelocephahis vanhornei and Dikelocephalus ininnesotensis ?? 396 63. Dikelocephalus hartti and Dikelocephalus f tribulis 398 64. Dikelocephalus ? dalyi, Saukia marica. Calvinella tcniusculpta and Conokephalina ornata 400 65. Saukia lodensis, Dikelocephalus texanus, Dikelocephahis ? limbatus and Saukia crassimarginata 402 66. Dikelocephalus ininnesotensis and Saukia crassimarginata .... 404 67. Saukia pepinensis, Saukia leucosia, Saukia pyrcne and Saukia fallax 406 68. Conokephalina misa, Osceolia osceola and Calvinella spiniger. . 408 69. Saukia tuardi and Saukia stosei 410 70. Calvinella o::arkensis, Calvinella neti'tonensis and Saukia stosei 412 Text figs. 13-16. Saukia coloradoensis 37^ 17. Saukia jiinia 378 18-20. Saukia rustica 383 INTRODUCTION Many years ag'o I planned an investi^s^arion of the genus Dikelo- cephalus, but under the pressure of other studies and administrative duties it was delayed. Dr. L. C. \A'^ooster in 1883, Dr. Cooper Curtice in 1884, and Dr. Charles Schuchert in 1896 all made extensive col- lections from the Cambrian of Wisconsin and Minnesota, and it is from this material that many of the illustrations in this paper are taken and the association of species determined. With but slight study in the past I have referred several species represented by fragments to Dikelocephalus, and also accepted similar NO. 13 DIKELOCEPHALUS AND OTHER GENERA 347 references of species by authors. Fortunately Dr. W. C. Brogger studied the genus and in 1886 proposed three new genera that served in a measure to bring order out of the confusion before existing. 1 have not been able to secure entire specimens of any species of Dikclocephalus (as restricted), but entire dorsal shields of the closely related Saukia lodensis (pi. 65) and Satikia crassiniarginata (pi. 66) give some conception of the probable form of the dorsal shield of the genotype, D. minnesotcnsis. I am indebted to Mr. Edgar E. Teller, of the Milwaukee IMuseum, for his permission to illustrate specimens of Satikia lodensis and to examine other material in his collection. ]\Ir. W. A. Finkelburg, of Winona, ]\Iinnesota, sent me numerous specimens from the St. Lawrence and Franconia formations about Winona and on the Wisconsin side of the Mississippi River. CLASSIFICATION The subfamily Dikelocephalinas Beecher ' was proposed by its author in 1897 to include the genera Dikelocephalus, Asaphelina and Crepicephalus. Just before Dr. Beecher's paper appeared, Dr. Brog- ger called attention to the resemblance between Asaplieliim miqiicH Bergeron and the Asaphidae,' and I agree with him that Asaphelina should be grouped under the Asaphidse and not the Dikelocephalinse. The third genus mentioned by Beecher, Crepicephalus Owen, as shown by entire specimens of C. texanus Shumard,^ appears to be more nearly related to the Oleninre. W^ith the elimination of Asaphelina and Crepicephalus from the Dikelocephalinae there remains of the genera referred to it by Beecher, only Dikclocephalus ; with this there is now included in this paper the genus Conokephalina (Brogger)^ with Conocephalites ornatits as the genotype. Brogger also included under Conokephalina, Dikclo- cephalus Osceola Hall, D. viisa Hall and D. spiniger Hall on account of their having narrow free cheeks, elongate palpebral lobes and an elongate, slightly narrowing glabella. Of these species D. niisa is retained under Conokephalina and D. osccola and D. spiniger are referred in this paper to other genera. Conokephalina is represented by several species in the Cambrian fauna of China." It is provisionally ^ Natural Classification of the Trilobites, American Journ. Sci., 4th ser., Vol. 3, 1897, P- 192. ^ Nyt Mag. for Naturvid., Vol. 36, 1897, p. 185. 'U. S. Geol. Survey. Monogr. z^, 1899, part i, pi. 65, fig. 5. * Geol. Foren. i Stockholm Forhandl., No. loi, Vol. 8, 1886, pt. 3, p. 206. ° Research in China, Vol. 3, Carnegie Institution of Washington, Pub. No. 54, 1913, Paleontology, The Cambrian Faunas of China, p. 138. 348 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 5/ placed in the subfamily DikelocephalinEe as it appears to be an inter- mediate form between Dikelocephahis and Ptychoparia as is sug- gested by Brogger. With the discovery of entire specimens of the genotype, C. ornatiis, it is possible that it may be placed under some other family or subfamily. There is evidently a group of forms that like Conocephalites (= Conokeplialina) emmrichi Barrande (Wal- cott)^ will need careful consideration when a review is made of the Olenidse. Three new genera, Saiikia, Osceolia and CalvincUa, are proposed in this paper and are referred to the Dikelocephalinge. With our present information, the following genera are included in the subfamily Dikelocephalinse : Dikelocephahis Owen, 1852 Conokephalina Brogger, 1886 ^aM^m Walcott, 1914 Osceolia Walcott, 19 14 Calvinella Walcott, 19 14 Observations on the genera.—Dikelocephahis (restricted) appears to be distinct from all other genera by the broad, flattened border of its cephalon, large eyes placed well back, large, broad subquadrangu- lar glabella with strong posterior furrow, and large, wide pygidum with broad, flattened border. Saukia has a narrow frontal border about the cephalon and a gla- bella proportionally more elongate than in Dikelocephahis. The pygid- ium of Saukia is less expanded and proportionally more elongate than that of Dikelocephalus. The cranidium of Brogger's genus Conokephalina (1886) has a somewhat similar form to that of Saukia, but the strong transverse posterior glabellar furrow of Saukia. and the absence of a clearly marked frontal limb in advance of the glabella serve to distinguish the cranidium of Saukia. The pygidium associated with Conokeph- alina ornata is transverse with a spinose margin, while that of Saukia is nearly as long as broad and the margin is unbroken by spines. Osceolia is characterized by its concave frontal limb, elongate pal- pebral lobes ; narrow fixed cheeks and transverse pygidium with its anterior segment extended beyond the margin as a long, strong spine. Calvinella is most like Saukia, from which it differs in form of glabella, presence of a strong occipital spine and proportionally more ^ Research in China, Vol. 3. Carnegie Institution of Washington, Pub. No. SA, 1913, Paleontology, The Cambrian Faunas of China, pi. 13, fig. 7. NO. 13 DIKELOCEPHALUS AND OTHER GENERA 349 elongate pygidium. It differs from Osceolia in frontal limb of cephalon ; presence of occipital spine and character of pygidium. Further observations on the genera will be found under the descrip- tion of each genus. SYNONYMIC REFERENCES The following is a list of the species that have been referred to Dikelocephalus ' and which are now referred to other genera. It is only approximately complete, as many references that occur in text- books and in general discussion of the fauna are omitted. FORMER GENERIC REFERENCE. PRESENT GENERIC REFERENCE. Dikelocephalus afUnis Billings (Geol. Surv. Canada, Pal. Foss., Vol. i, 1865, p. 197) Platycolpus Raymond.^ Dikelocephalus angusticauda (Angelin) Lin- narsson, Brogger (Die Sil. Etagen 2 und 3, • " Kristiania, 1882, p. 126) Apatokephalus Brogger. Dikelocephalus {? ) angustifrons Walcott (Monogr. U. S. Geol. Survey, Vol. 8, 1884, p. 42, pi. 10, figs. I, la, lb) Lisania Walcott. Dikelocephalus barabuensis Whitfield (Ann. Rep. for 1877, Wis. Geol. Survey, 1878, p. 63) .Platycolpus Raymond. Dikelocephalus ? baubo Walcott (Proc. U. S. Nat. Museum, Vol. 29, 1905, p. 91) Ptychaspis Hall. Dikelocephalus ? bavaricus (Barrande) Brog- ger (Nyt Mag. for Naturvid., Vol. 36, 1898, p. 212) Genus undt. Dikelocephalus belli Billings (Geol. Surv. Canada, Pal. Foss., Vol. i, 1865, p. 403, text fig. 378) xinomocarella Walcott. Dikelocephalus billingsi Linnarsson (Geol. Foren. Stockholm Forhandl., Vol. 2, 1875, p. 492, pi. fig. I ) Acerocare Angelin. Dikelocephalus bilobatus Hall and Whitfield (U. S. Geol. Expl. 40th Pari., Vol. 4, 1877, p. 226, pi. 2, fig. 36) Platycolpus Raymond. Dikelocephalus ? brizo Walcott (Proc. U. S. Nat. Mus., Vol. 29, 1905, p. 92) Ptychaspis Hall. Dicellocephalus broggeri Moberg (Aftryck ur Kongl. Fysiogr. Sallsk. Handl. Lund, Bd. 17, 1906, p. 87, pi. 5, figs. 7, 8) Genus undt. cf. Platycolpus Raymond. ^ The original spelling of the genus is adhered to in this paper, but under synonymic references the spelling used by each author has been retained, the alphabetical sequence according to species names being followed. ^Memoirs Victoria Memorial Museum, Geol.* Survey Canada, Bull, i, 1913, p. 63. 350 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 5/ FORMER GENERIC REFERENCE. PRESENT GENERIC REFERENCE. Dikeloccphalus ccJiicus Salter (Mem. Geol. Surv. Great Britain. Vol. 3. 1866, p. 304) Undt. genus. Species founded on distorted pygidia. Dikelocephaliis cristatus Billings (Canadian Nat. Geol., Vol. 5, i860, p. 312, text fig. 10) . . Conokephalina Brogger ? Dikelocephaliis {?) corax Billings (Geol. Surv. Canada, Pal. Foss., Vol. i, 1865, p. 334. text fig. 3220-^) Genus undt. Dikelocephaliis crassimargiiiatus Whitfield (Geol. Wisconsin, Vol. 4, 1882, p. 344, pi. 27, fig. 14) Saukia Walcott. Dikelocephaliis dcvinei Billings (Geol. Surv. Canada, Pal. Foss., Vol. i, 1865, p. 195, fig. 180) Ptychoparia ? Corda. Dikelocephalus dicraeurus (Angelin) (Lin- narsson) Brogger (Die Sil. Etagen 2 und 3, Kristiania, 1882, p. 126) Dikelokephalina dicracura. Dikelocephalus discoidalis Salter (Mem. Geol. Surv. Great Britain, Vol. 3, 1866, p. 304) . .. .Genus undt. Species founded on fragments of distorted cranidia. Dikelocephalus dubius (Linnarsson) Brogger (Nyt Mag. for Naturvid., Vol. 35, 1897, P- 175, figs, 5a-fc) Apatokephaliis dubius. Dikelocephalus eatoni Whitfield (Ann. Rep. Surv. Wisconsin for 1877, 1878, p. 65) Platycolpus Raymond. Dikelocephalus (f) expansus Walcott (Monogr. U. S. Geol. Surv., Vol. 8, 1884, p. 45, pL 9, fig. iq) DoHchometopus Angelin. Dikelocephalus Unalis Walcott (Monogr. U. S. Geol. Surv., Vol. 8, 1884, p. 89) ipatokcphalus Brogger (1896). Dikelocephalus Hagricaudiis White (Geog. and Geol. Expl. and Surv. West looth Merid., Vol. 4, pt. I, 1875, p. 60) Zacanihoides Walcott. Dikelocephalus HabelUfer Hall and Whitfield (U. S. Geol. Expl. 40th Pari., Vol. 4, 1877, p. 227, pi. 2, figs. 29, 30) Apatokephalus Brogger (1896). Dikelocephalus florentinensis Etheridge (Rec- ords Australian Museum, Sydney, Vol. 5, 1905, p. 99, pl. 10, fig. 4) Dikelokephalina Brogger. Dikelocephalus {Centrapie lira ?) furca Salter (Mem. Geol. Surv. Great Britain, Vol. 3, 1866, p. 303) Dikelokephalina Brogger. Dikelocephalus ? gothicus Hall and Whitfield (U. S. Geol. Expl. 40th Pari., Vol. 4, 1877, p. 242) Olenoides wasatchensis Hall and Whitfield. Dikelocephalus grauiilosiis Owen (Rept. Geol. Surv. Wis., Iowa, and Minn., 1852, p. 57s) -Ptychaspis Hall (1863). NO. 13 DIKELOCEPHALUS AND OTHER GENERA 351 FORMER GENERIC REFERENCE. PRESENT GENERIC REFERENCE. Dikeloccphalus hartti (Walcott) Stose (U. S. Geol. Surv. Geol. Atlas, U. S. Folio No. 170, 1909, p. 6) Dikeloccphalus Owen. Dikeloccphalus hisinge7-i Billings (Geol. Surv. Canada, Pal. Foss., Vol. i, 1865, p. 196) Lisauia Walcott ? Dicclloccphalus inexpectans Walcott (Monogr. U. S. Geol. Surv., Vol. 8, 1884, p. 90, pi. I, fig. 10) Coiwkcphalina Brogger. Dicclloccphalus ? interprcs Read (Mem. Geol. Surv. India, ser. 15, Vol. 7, Mem. No. i, Cambrian Fossils of Spiti, 1910, p. 38, pi. 5, figs. 9-13) Ptychoparia Corda ? Dicclloccphalus iole Walcott (Monogr. U. S. Geol. Surv., Vol. 8, 1884, p. 43, pi. 10, fig. 19) . Conokcphalina Brogger ? Dikeloccphalus iozvensis Owen (Geol. Surv. Wis., Iowa, and Minn., 1852, p. 575) Crepicephalus Owen. Dikeloccphalus latifrons Shumard (Trans. Acad. Sci., St. Louis, Vol. 2, 1863, p. 101) .. .Ptychoparia wisconsincnsis (Owen). Dicclloccphalus ? leptccnarum Wiman (Arkiv for Zoologi, Bd. 3, 1906, No. 24, p. 5, pi. 12, figs. 1-3) Saukia Walcott ? Dikeloccphalus lodensis Whitfield (Geol. Wis- consin, Vol. 4, 1882, p. 188, pi. 10, fig. 14, pi. 27, figs. 12, 13) Saukia Walcott. Dikeloccphalus (Centroplcura) lovcni (Ange- lin) Koken (Die Leitfossilien, Leipzig, 1896, p. 17) Paradoxides loveni Angelin. Dikeloccphalus magnificus Billings (Geol. Surv. Canada, Pal. Foss., Vol. i, 1865, p. 400).... New genus Hungaia Walcott (MSS.). Dikclloccphalus ? marcoui Whitfield (Bull. American Mus. Nat. Hist., Vol. i, 1884. p. 150) Olcnoidcs Meek. Dikeloccphalus niarica Walcott (Monogr. U. S. Geol. Surv., Vol. 8, 1884, p. 44, pi. 10, fig. 13) . -Saukia Walcott Dikeloccphalus megalops Billings (Geol. Surv. Canada, Pal. Foss., Vol. i, 1865, p. 402,) ... .Conokcphalina Brogger. Dicclloccphalus micropthalmiis Holm (Geol. Foren. i Stockholm Forhandl., Vol. 19, 1898, p. 466) Anoniocarc Angelin ? Dicclloccphalus ininncsotensis ?. Identified by R. P. Whitfield. (Monogr. U. S Geol. Sur- vey, Vol. 12, 1886, p. 60) Saukia coloradocnsis Walcott. Dikeloccphalus minnesotensis linibatus Hall (Sixteenth Ann. Rep. N. Y. State Cab. Nat. Hist., 1863, pi. 141, pi. 9, fig. 12) Dikeloccphalus linibatus Hall. Dikeloccphalus miniscaensis Owen (Geol. Surv. Wis., Iowa, and Miim.. 1852, p. 574) Ptychaspis Hall. 352 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 FORMER GENERIC REFERENCE. PRESENT GENERIC REFERENCE. Dicellocephalus misa Berkey (Am. Geologist, Vol. 21, 1898, p. 290, pi. 20, figs. 12, 13) Anomocare ? Angelin. Dikelocephalus misa Hall (Sixteenth Ann. Rep. N. Y. State Cab. Nat. Hist., 1863, p. 144, pi. 8, fig. 15 ; pi. 10, figs. 4, s) Conokephalina Brogger. Dikelocephalus missisquoi Billings (Geol. Surv. Canada, Pal. Foss., Vol. i, 1865. p. 199) New genus. Dikelocephalus multicinctiis Hall and Whitfield (U. S. Geol. Expl. 40th Pari., Vol. 4. i877, p. 226, pi. 2, fig. 36) Apatokephaliis Brogger (1896). Dikelocephalus nasutus Walcott (Monogr. U. S. Geol. Surv., Vol. 8, 1884, p. 40, pi. 10, fig. 15) Proampyx Freeh. Dikelocephalus neivtonensis Weller (Geol. Surv. New Jersey, Rep. on Pal., Vol. 3, 1903, pp. 121-122, pi. 3, figs. 1-7) Calvinella Walcott. Dikelocephalus osceola Hall (Sixteenth Ann. Rep. N. Y. State Cab. Nat. Hist, 1863, p. 146, pi. 10, fig. 18 ; pi. 7, fig. 49) Osccolia Walcott. Dikelocephalus oweni Billings (Canadian Nat. Geol., Vol. 5, i860, p. 310, text fig. 8) Anomocarella Walcott ? Dikelocephalus pauper Billings (Geol. Surv. Canada, Pal. Foss., Vol. i, 1865, P- 200) Ptychaspis Hall ? Dikelocephalus pepinensis Owen (Rept. Geol. Surv. Wis., Iowa, and Minn., 1852, p. 574, pi. I, figs. 9, 9a) Saukia Walcott. Dikelocephalus planifrons Billings (Canadian Nat. Geol., Vol. 5, i860, p. 309, text fig. 6) . .Anomocarella Walcott ? Dikelocephalus quadriceps Hall and Whitfield (U. S. Geol. Surv. 40th Pari., Vol. 4, 1877, p. 240) Olenoides Meek. Dikelocephalus richmondensis Walcott (Monogr. U. S. Geol. Surv., Vol. 8, 1884, p. 41, pi. ID, fig. 7) Ptychoparia Corda. Dikelocephalus roemeri Shumard (American Journ. Sci., 2d sen. Vol. 32, 1861, p. 220) . . . Ptychoparia Corda. Dikelocephalus selectus Billings (Geol. Surv. Canada, Pal. Foss., Vol. i, 1865, p. 199) Ptychaspis Hall ? Dikelocephalus serratus (Boeck) (Linnars- son) Brogger (Die Sil. Etagen 2 und 3, Kris- tiania, 1882, p. 126) Apatokephahis Brogger. Dikelocephalus sesostris Billings (Geol. Surv. Canada, Pal. Foss.. Vol. i, 1865, p. 198) Ptychaspis Hall. Dicellocephalus ? sinensis Bergeron (Bull Soc. geol. de France, Vol. 27, 1899, p. 508) . .Stephanocare Monke. Dikelocephalus spiniger Hall (Sixteenth Ann. Rep. N. Y. State Cab. Nat. Hist., 1863, p. 143. pl. 10, figs. I, 2, 3 ?) Calvinella Walcott. NO. T3 DIKEr.OCEPIIALUS AND OTHER GENERA 353 FORMER GENERIC REFERENCE. PRESENT GENERIC REFERENCE. Dikelocephalus tasmaiiiciis Etheridge (Proc. Royal Soc. Tasmania for 1882, 1883, p. 155, pi. I, fig. 4) Dikclokel>halina Brogger. Dicellocephahis f villcbruni Bergeron (Bull. Soc. geol. de France, 3d ser., Vol. 23, 1895, P- 473, pl- 5, figs. 1,2) Dikclokephalina Brogger. Dikellocephalus ivahsatchcnsis Hall and Whit- field (U. S. Geol. Expl. 40th Pari., Vol. 4- 1877, p. 241 ) Olenoides Meek. STRATIGRAPHTC POSITION OF THE DIKELOCEPHALIN^ It has been evident for several years that the various Cambrian formations of the Upper Mississippi Valley, which had been referred first to the Potsdam and then to the St. Croix sandstones, needed careful revision in relation to their stratigraphic position and suc- cession. The original classification of Owen (1852) was superseded by the classification of the Minnesota Survey for the Minnesota sections, and for Wisconsin by the classification of the Geological Survey of Wisconsin. The two latter classifications were as follows : Wisconsin Minnesota 1. Madison Sandstone. i. Jordan Sandstone. 2. Mendota Limestone. 2. St. Lawrence Limestone. Calcareous Sandstone. Shale. Fine quartzose Sandstones. Coarse quartzose Sandstone. 2is. In many localities other fossiliferous beds occur in the central and lower portions. Massive-bedded, rather coarse- grained sandstone, with a thin bed of shale at the base and shaly sandstone near the middle. Fossils at the top and base, consisting almost entirely of shells of Dicel- lomus and LingiileUa. Mostly thin-1 edded, in part shaly sandstone, with many fossiliferous layers, including Owen's Menom- onie and Wooster's Eau Claire trilobite zones. Usually a coarse white friable sandstone with Dicel- !omits and Lingulella'at the base. Numerous characteristic trilobites, Crepicephalus iowensis being one of the best of the guide fossils. A series of coarse sandstones and grits resting on pre-Cambrian granite. About 225 feet are shown in the bluffs at Eau Claire and 50 feet of the base at Chippewa Falls, Wisconsin. Except Scolithns bor- ings no fossils have been found. NO. 13 DIKELOCEPHALUS AND OTHER GENERA 355 Jordan formation.—In Wisconsin this is a rather coarse-grained, thick-bedded, compact but soft. sHghtly calcareous, Hght-colored sandstone.^ In Minnesota it is described as white and sihceous and locally forming rather firm layers that break up into angular blocks.^ As far as known the Jordan sandstone as limited by Ulrich has not furnished any fossils in situ. There is, however, a fauna collected from sandstones in the vicinity of Devil's Lake, Sauk County, Wisconsin, that may belong at this horizon. It includes from locality 8ib the following species : Arenicolitcs woodi Whitfield Saiikia cf. pyrciic Walcott Finkelnburgia finkelnburgi (Walcott) Osceolia cf. osccola (Hall) Syntrophia barabuensis (A. Winchell) Agraulos ? sp. undt. Straparolliis ? {Ophilcta ?) primor- Ptychasp's sp. undt. dialis Winchell Platycolpus barabuensis (Whitfield) Dikcloccphahis cf. limbatus Hall Plalycolpus cf. catoiti (Whitfield) Saukia cf. crassimarginata (Whit- Illccnurus sp. undt. field) Conaspis cf. aiiatiiia (Hall). The specimens occur in a friable sandstone similar to that of the Jordan formation and unlike the supposedly older, more or less cal- careous St. Lawrence formation. The fauna is of the same general facies as that of the upper portion of the St. Lawrence formation, but the trilobites differ in minor details, and there are also present two trilobites closely simulating Platycolpus barabuensis and P. catoni (Whitfield). The two latter are types suggesting the suc- ceeding Ozarkian period, the typical varieties of the species, being characteristic of the superjacent Mendota dolomite. St. Lawrence formation.—The eastern Wisconsin phase of this formation is described as consisting of alternating strata of arena- ceous magnesian limestone, sandy calcareous shales, and shaly and calcareous sandstones.^ In Minnesota the St. Lawrence limestone is formed of an upper regularly bedded magnesian limestone from 30 to 50 feet in thickness, and " below these massive layers, which constitute a part of the pre- cipitous bluffs of the county, there is a varying thickness of more fragile indescribable rock, which can best be defined by Dr. Owen's term siliceo-argillaceous dolomite, with occasional layers of an inch or two of crumbling white sand. There is also a slow transition from the crumbling sandstone of the St. Croix to the dolomitic firm rock of the St. Lawrence At ten or fifteen feet higher [from the base] the rock has assumed that character which is almost indescrib- ' Chamberlin, Geol. Wisconsin, Vol. 2, 1877, p. 260. 'Winchell, N. H., Geol. Minnesota, Vol. i, 1884, p. 253. Tieol. Wisconsin Vol. 2, 1877, p. 261. 356 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 able, being greenish and shaly and yet not a shale, calcareous but not a limestone, magnesian but not a dolomite, finely siliceous but not a sandstone. This character continues through a thickness of forty to fifty feet of strata." ' . . . . St. Lawrence fauna.—The fauna of the upper beds at Osceola, Wisconsin (Locality 78), includes a large group of species as follows : LingulcUa mosia (Hall) Lingulella mosia osceola (Walcott) Lingulella winona (Hall) Lingulella winona convexa (Walcott) Billingsclla coloradoensis (Shumard) Finkelnburgia finkelnburgi (Walcott) Finkelnburgia osceola (Walcott) Finkelnburgia osceola corrugata (Walcott) Syntrophia barabuensis (A. Winchell) Hyolithes ? corrugatus Walcott Spirodentaliuni osceola Walcott Holopea sweeti Whitfield Metoptoma sp. Platyceras ? Owenella antiquata (Whitfield) Murchisonia sp. undt. Agnostus disparilis Hall Ptychaspis sp. (also at Devils Lake, 81) Ptychaspis ? sp. Dikelocephalus ? limbatus Hall Dikelocephalus minnesotensis Owen ? Saukia leucosia Walcott Sattkia pyrene Walcott Osceolia osceola (Hall) Ptychoparia ? bindosa (Hall) Ptychoparia sp. lllcenurus quadratus Hall Triarthrella auroralis Hall At an horizon 50 feet (15 m.) above the St. Croix River Saukia crassimarginatus (Whitfield) (78b) occurs in association with sev- eral of the species in above list. Calvinella spiniger Hall is abundant at about this horizon in the calcareo-arenaceous beds of locality 83' at Trempealeau, and it also occurs lower down in this section at 83'. In the lower arenaceo-calcareous beds Dikelocephalus minneso- tensis has its greatest development. This sub-fauna includes : Obolus {Westonia) aurora (Hall) Obolus {Westonia) stoneanus (Whit- field) Lingulella mosia (Hall) Lingulella oweni (Walcott) Lingulella winona (Hall) Lingulella winona convexa (Walcott) Finkelnburgia osceola (Walcott) Syntrophia primordialis (Whitfield) Serpulites murchisoni Hall Owenella antiquata (Whitfield) Owenella vaticina (Hall) Dikelocephalus minnesotensis Owen Saukia crassimarginata (Whitfield) Saukia lodensis (Whitfield) Saukia pepinensis (Owen) Calvinella spiniger (Hall) Ptychoparia binodosa (Hall) Triarthrella auroralis Hall Ptychaspis n. sp. lllcenurus quadratus Hall lllcenurus n. sp. Aglaspis eatoni Whitfield Aglaspis barrandei Hall Dendrograptus hallanus Prout is not represented in our collection. Known from Osceola, Wisconsin, and Lake City, ^Minnesota. ' Geol. Minnesota, Vol. i, 1884, p. 255. NO. 13 DIKELOCEPHALUS AND OTHER GENERA 357 The Franconia formation.—In Wisconsin and Minnesota beneath the strata referred to the St. Lawrence series are found more or less calcareous shales and sandstones. The only trace of the Dikelo- cephalinse is in the upper arenaceous shales and thin layers of sand- stone of the Franconia horizon. This is found in Conokephalina misa (Hall). The associated fauna is quite distinct from that of the St. Lawrence formation, and includes (79a, 79b, 80a, 97, 99a, 100) : Obolus matinalis (Hall) Synirophia primordialis argia Walcott Oboliis mickwitzi Walcott Palaacmcea irvingi Whitfield Obolus (Westonia) aurora (Hall) Eccyliomphalus n. sp. Lingulclla mosia (Hall) Agnostus josepha Hall Lingiilella mosia osceola (Walcott) Agnostus parilis Hall Lingulella oweni (Walcott) Lonchoccphalus hamulus Owen Lingulella phaon (Walcott) Lonchocephalus wisconsinensis Owen Lingulella similis (Walcott) Ptychaspis granulosa (Owen) Lingulella winona (Hall) Ptychaspis miniscaensis (Owen) Lingulella winona convexa (Walcott) Ptychaspis striata Whitfield Lingulella (Lingnlepis) acuminata Chariocephalus ivhitfieldi Hall (Conrad) Chariocephalus sp. Dicellomus politus (Hall) Conaspis^ anatina (Hall) Eoorthis f diablo Walcott Conaspis bipunctata (Shumard) Eoorthis remnicha (N. H. Winchell) Conaspis eryon (Hall) Eoorthis remnicha sulcata (Walcott) Conaspis nasuta (Hall) Eoorthis remnicha winHeldensis Conaspis oweni {^HaW) ? (Walcott) Conaspis patersoni (Hall) Eoorthis sp. Conaspis perseus (Hall) Otusia sandbergi N. H. Winchell Conaspis ? shumardi (Hall ?) Billingsella coloradocnsis (Shumard) Ptychoparia diademata (Hall) Finkelnburgia finkelnburgi (Walcott) EUiptocephalus ? curtus (Whitfield) Finkelnburgia osceola (Walcott) Conokephalina misa (Hall) Syntrophia primordialis (Whitfield) ^ Conaspis Hall.* Dr. Th. Lorenz ^ places two species under the genus Macrotoxus: Anomocare angelini Gronwall [1902] and Conocephalites perseus Hall [1863]. I think A. angelini Gronwell is a true Anomocare and should be retained in that genus, which makes Macrotoxus a synonym of Conaspis Hall. The genotype of Conaspis will now be C. perseus (Hall). It is representa- tive of a group of species in the Upper Cambrian formations allied to Ptycho- paria that are characterized by a subconical glabella, medium sized eye-lobes, rather strong postero-lateral limbs, narrow fixed checks, and with facial sutures extending almost directly forward from the eye lobes so as to form a narrow frontal limb ; the frontal rim is usually well defined and cut obliquely by the facial sutures. The species I now refer to Conaspis from the St. Croixan of the upper Mississippi Valley are ; * Sixteenth Ann. Rept. New York State Cat. Nat. Hist., 1863, p. 152. ^Zeitschr. deutsch. geol. Gesellsch., Bd. 58. 1906, p. 61. 358 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 5/ Fauna of Eau Claire formation.—The fauna of the Eau Claire sandstones is marked especially by Anomocarella zvoostcri, Crepi- cephalus texanus, and Crepicephalus ioivensis. The fauna includes near Eau Claire, Wisconsin, the following species at the highest horizon on Mount Washington, locality 78a : Oboliis sp. undt. Pagodia thea (Walcott) Diccllomiis pectenoides (Whitfield) Crepicephalus iozvciisis Owen Dicellomns politus (Hall) At a slightly lower horizon the following species occur, locality gSx: Worm borings Ptychoparia chippcwaensis Owen Obolus matinalis (Hall) ' Ptychoparia optata Hall Lingulella mosia (Hall) Crepicephalus iowensis Owen Lingulclla phaon (Walcott) Crepicephalus texauus Shumard Dicellomus politus (Hall) Agraulos sp. undt. Hyolithes primordialis Hall Pagodia thea (Walcott) Stenotheca sp. undt. Anovwcare sp. undt. Agnosius josepha Hall Anomocarella onusta (Whitfield) Ptychoparia ? calymenoides Whitfield Anomocarella woosteri (Whitfield) Additional species occur at other localities as follows : Obolus mickivitci Walcott Billiiigsella coloradoeiisis (Shumard) Obolus namouna Walcott Pcmphigaspis bullata Hall Obolus rhea Walcott Lonchocephalus ? minor (Shumard) Obolus (Westonia) aurora (Hall) Ptychoparia ? quadrata (Whitfield) Lingulella winona (Hall) Anomocarella ? winona (Hall) Lingulella winona convexa (Walcott) Lingulella (Lingulepis) acuminata (Conrad) Pcmphigaspis bullata seems to be confined to the uppermost beds referred to the formation. Stratigraphic range of the genera.—From the preceding lists it will be seen that with our present information the genera of the Dikelo- cephalinse in the central region of the continent range from the sand- Conocephalites anatinus Hall Conoccphalites perseus Hall Conocephalitcs eryon Hall Ptychoparia patersoni (Hall) Conocephalites nasutus Hall Arioncllus bipunctatiis Shumard ? Conocephalitcs oiveni Hall [All described in Sixteenth Ann. Rept. N. Y. State Cab. Nat. Hist., 1863.] That from the Upper Cambrian of Texas is : Ptychoparia llauocnsis Walcott [Described in Proc. U. S. Nat. Mus.. Vol. 13, 1890, pp. 272-274.] NO. 13 DIKELOCEPHALUS AND OTHER GENERA 359 Stones of the Franconia formation upward through the St. Lawrence formation into the base of the Jordan sandstone of Wisconsin and Minnesota. In Missouri Calinnella ozarkcnsis (pi. 70, figs. 1-6) is associated with a large and varied fauna in which the Gastropoda and Cephalo- poda are strongly developed. It thus appears to belong in a later fauna than the Jordan. Calvinella tenuisculpta from the lower Pogonip limestone of Nevada is also from about the same horizon as C. osarkensis. With it are associated the following : (Locality 201a) "Lower Ordovician " (Ozarkian or Canadian) : Pogonip limestone, east slope of the ridge east of Hamburg Ridge, Eureka district, Eureka County, Nevada (C. D. Walcott, 1882) : Obolus {Westonia) iphis Walcott Apatokephalus Unalis (Walcott) Lingulella pogonipcnsis (Walcott) Conokephalina incxpectans (Wal- Acrothele sp. cott) Acrotreta idahoensis Meek Agraulos f annectans (Walcott) Schizamhon typicalis Walcott Aitomocarclla owcni Meek and Hay- Eoorthis hambmgensis Walcott den Syntrophia nundina Walcott Amphion ?f sp. undt. Tellinomya ? hamhurgcnsis Walcott Chuangia mccoyi Walcott Agnostics prolongns Hall and Whit- lUccnurus ? eurekensis Walcott field Asophns ? carihoucnsis Walcott Traces of Dikelocephahis are found in the southern Mississippi area in Oklahoma and Texas in the Upper Cambrian. The associated fauna in Texas includes Saiikia fallax and in addition the following: (Locality 70a) (below the fauna of locality 70) Upper Cambrian: Wilberns formation ; Baldy Mountain, near Morgan's Creek, 8 miles (12.8 km.) northwest of Burnet, Burnet County, Texas (C. D. Wal- cott, 1884). BillingscUa coloradoensis (Shumard) Dikelocephahis texanus Walcott Nileus ? dia (Walcott) Saukia fallax Walcott Lonchocephaliis ivisconsincnsis Owen Osceolia osccola (Hall) Dikelocephahis.-—Of the seven species referred to the genus Dikelo- cephahis as restricted in this paper the stratigraphic position of all is knowm with the exception of D. ? dalyi n. sp. The type species of the genus, D. minnesotensis Owen, is recorded in literature as occurring at many localities, but I have inserted in this paper only those localities represented in the United States National Museum collections. It will be necessary to have more systematic and careful stratigraphic work and collecting done before any more accurate statement can be made. 360 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 DikelocepJialiis minncsotensis Owen as now restricted does not occur in the supposed Jordan formation fauna exposed about Devils Lake, Wisconsin. The genus is there represented by a variety of D. f limbatiis. The typical form of this species occurs in the upper St. Lawrence beds at Osceola (78, 78b). There are fragments of a large trilobite that sugg-est D. minnesotensis at Osceola, but the identifica- tion is too uncertain to be of value. As far as known to me, D. min- ncsotensis does not occur in the Madison sandstone of the post- Cambrian. The species is found at the following, among other localities, in association with other genera and species as given in the following lists : (Locality 85) Upper Cambrian : St. Lawrence formation at Prairie du Sac, Sauk County, Wisconsin (Cooper Curtice, 1884). Oholus (Wcstonta) aurora (Hall) Obolus (Wcstonia) stoneanus (Whit- field) Lingulella viosia (Hall) Lingulella oweni (Walcott) Lingulella winona (Hall) Lingulella winona convexa (Wal- cott) Oivcnclla antiqiiata (Whitfield) Dikcloccphaliis minnesotensis Owen Saukia crassimarginata (Whitfield) Saukia lodensis (Whitfield) Saukia pcpinensis (Owen) Illcemirus quadratus Hall Aglaspis barrandei Hall Aglaspis eatoni Whitfield (Locality 86) Upper Cambrian: St. Lawrence formation at Van Ness quarry, Gibraltar Bluff, Lodi, Columbia County, Wisconsin (L. C. Wooster, 1883; Cooper Curtice, 1884). Obolus (JVestonia) aurora (Hall) Lingulella mosia (Hall) Lingulella oweni (Walcott) Dikelocephalus viinnesotensis Owen Saukia lodensis (Whitfield) Illcenurus quadratus Hall Aglast^is barrandei Hall (Locality 113) Upper Cambrian: St. Lawrence formation at La Grange Mountain (or Barn Bluff), near Red Wing, Goodhue County, Minnesota (Cooper Curtice, 1884). Lingulella mosia (Hall) Lingulella winona (Hall) Serpulites murchisoni Hall Owenella vaticina (Hall) Triartlirella auroralis Hall Ptychaspis sp. ? Dikelocephalus minnesotensis Owen Saukia pepinensis (Owen) Saukia.—The genotype of the genus, Saukia lodensis, occurs only in the Upper Cambrian St. Lawrence formation. It is associated at localities 85 and 86 with the species listed above. Saukia crassimarginata has a somewhat greater vertical range as it occurs with S. lodensis, and also in the overlying Jordan sandstone. At locality 78b it is associated with the following species : NO. 13 DIKELOCEPHALUS AND OTHER GENERA 361 Upper Cambrian : (78b) St. Lawrence formation, 50 feet (15.2 m.) above St. Croix River, near the landing- at Osceola, Polk County, Wisconsin (Cooper Curtice, 1884). Lingulella mosia (Hall) Dikelocephalus ininnesotensis Owen ? Lingulella similis (Walcott) Saukia crassimarginata (Whitfield) Finkclnburgia osceola (Walcott) Osceolia osceola (Hall) Ozvenella cf. antiquata (Whitfield) Illcenurus quadratus Hall Dikelocephalus ? limbatus Hall Saukia pepinensis (Owen) is found abundantly in the St. Law- rence formation (113, p. 360). Saukia fallax (Locality 70a, p. 359) from Texas appears to be an Upper Cambrian species restricted to one locality and horizon as far as now known. Saukia leucosia and 6^. pyrene both occur in the upper portion of the St. Lawrence formation at locality 78 in the following associa- tion: Locality 78 : Upper Cambrian : St. Lawrence formation ; quarry near St. Croix River, in suburbs of Osceola, Polk County, Wisconsin (L. C. Wooster, 1883). Obolus (IVestonia) aurora (Hall) Spirodentalium osceola Walcott Lingulella mosia (Hall) Ouieiiella antiquata (Whitfield) Lingulella mosia osceola (Walcott) Holopea ? siveeti Whitfield Lingulella winona (Hall) Ophileta (Raphistoma) primordialis Lingulella winona convexa (Walcott) A. Winchell Billingsella coloradoensis (Shumard) Dikelocephalus ? limhatus Hall Finkelnburgia finkelnburgi (Walcott) Saukia leucosia Walcott Finkelnburgia osceola (Walcott) Saukia pyrene Walcott Finkelnburgia osceola corrugata Osceolia osceola (Hall) (Walcott) Illcenurus quadratus Hall Syntrophia barabuensis (A. Winchell) Saukia marica is at the upper line of the Cambrian in Nevada. At locality 62 it is associated with the following : Upper Cambrian: (62) Limestone in the Dunderberg shale in canyon immediately north of Adams Hill, Eureka district. Eureka County, Nevada (C. D. Walcott, 1880). Micromitra sculptilis Meek Agnoslus prolongus Hall and Whit- Obolus discoideus (Hall and Whit- field field) Pagodia breviceps ? (Walcott) Lingulella manticula (White) Saukia marica (Walcott) Lingulella punctata (Walcott) Arcthnsina ? americana Walcott Acrotreta spinosa Walcott Agnostus communis Hall and Whit- field 362 SMITHSONIAN MISCELLANEOUS COLLECTIONS \'0L. 57 Both Saukia stosei and 6^. wardi occur in the great Cambro-Ordo- vician limestones of the Appalachian region at about the horizon of the upper limit of the Upper Cambrian or possibly Lower Ozarkian. Osceolia.—Osceolia osceola is associated with the St. Lawrence fauna in Wisconsin (Localities 78 and 83', see lists of fauna, pp. 356, 361). In Texas (Locality 70a, p. 359) and Nevada it is identi- fied from the Upper Cambrian. In Nevada it occurs (Locality 66) with the following species : Upper Cambrian: (66) Dunderberg shale, on the first ridge north of the Dunderberg mine, Eureka district. Eureka County, Nevada (C. D. Walcott, 1880). Obolus discoideus (Hall and Whit- Agnostns tumidosus Hall and Whit- field) field Agnostus communis Hall and Whit- Lisania angustifrons Walcott field Osceolia osceola (Hall) Agnostus prolongus Hall and Whit- Euloma afUnis Walcott field Arethusina ? americana Walcott Calvinella.—This genus is essentially one of the transition forms between Cambrian and Ozarkian. Calvinella spiniger is known only with the St. Lawrence fauna (p. 356). Calvinella osarkensis in the Eminence fauna, C. newtonensis in the Kittatinny limestone, and C. tenuisculpta in the lower Pogonip limestone (p. 359). Calvinella neivtonensis occurs with the following species at locality lie: Lower Ozarkian: (iic) Lower part of Kittatinny limestone, O'Donnell and McManniman's quarry, Newton, Sussex County, New Jersey (H. E. Dickhaut, 1901). Obolus (Westonia) stoneanus (Whit- Ptychoparia newtonensis WeWer field) variety or n. sp. Anomocare ? parvula Weller Boorthis newtonensis (Weller) Calvinella newtonensis (Weller) Conokephalina.—This genus occurs only in the upper beds of the Franconia formation. The one species, C. misa (Hall), has been found in association with species of trilobites of the genera Chario- cephalus, Lonchocephalus, Ptychaspis, and Ptychoparia. and the brachiopod Billingsella coloradoensis. NO. 13 DIKELOCEPHALUS AND OTHER GENERA 363 DESCRIPTION OF GENERA AND SPECIES Genus DIKELOCEPHALUS' Owen Dikelocephalus Owen, 1852, Rep. Geol. Surv. Wis., Iowa, and Minn., p. 573. (Description of genus and observations.) Dikelocephalus Owen, Barranue, 1853, Neues Jahrb. fiir Min., Geol. und Geog., p. 336. (Comments on relation of Dikelocephalus to Ogygia.) Dikelocephalus Owen, Emmons, 1855, American Geol., Vol. i, pt. 2, p. 220. (Summarizes Owen's description of genus.) Dikelocephalus Owen, Billings, i860, Canadian Nat. Geol., Vol. 5, p. 306. (Comments on genus and refers several species to it.) Dikelocephalus Owen, Hall, 1863, Sixteenth Ann. Rep. N. Y. State Cab. Nat. Hist., p. 137. (Reprints Owen's description, comments on the genus and describes three new species.) Dicellocephahis Owen, Dana ?, 1864, American Journ. Sci. and Arts, 2d ser.. Vol. 2)7, P- 139- (Changes spelling of name. The article is unsigned but was in all probability written by Prof. James D. Dana.) Dikelocephalus Owen, Billings, 1865, Geol. Surv. Canada, Pal. Fossils, Vol. I, p. 399. (Reprints remarks of i860, noted above.) Dikelocephalus Owen, Salter, 1866, Mem. Geol. Surv. Great Britain, Vol. 3, p. 303. (Comments on genus and refers four species to it.) Dikelocephalus Owen, Hall, 1867, Trans. Albany Inst., Vol. 5, p. 116. (Re- print of article of 1863.) Dikellocephalus Owen, Hall and Whitfield, 1877, U. S. Geol. Expl. 40th Parallel, Vol. 4, p. 225. (Mentions genus and refers three new species to it.) Dicellocephahis Owen, Whitfield, 1878, Ann. Rep. Wisconsin Geol. Surv. for 1877, p. 63. (Notes finding of uncompressed specimens of genus and refers two new species to it.) Dikelocephalus Owen, Salter, 1881, Mem. Geol. Surv. Great Britain, Vol. 3, 2d ed., p. 497. (Reprint of paper of 1866.) Dikellocephalus Owen, Whitfield, 1882, Geol. Wisconsin, Vol. 4, p. 200. (Reprint of paper of 1878, with illustrations of the two species described under the genus.) Dikellocephalus Owen, Dames, 1883, China, Richthofen, Vol. 4, pp. 5, 6, (Comments on species referred to genus.) Dicellocephalus Owen, Matthew, 1893, Trans. Royal Soc. Canada, Vol. 10, Sec. 4, p. ID. (Discusses the geographic and stratigraphic distribution of the genus and the validity of the generic reference.) Dikelokephalus Owen, Brogger, 1897, Nyt Mag. for Naturvid., Vol. 2^, PP- i79> 182, 183. (Discusses questions of species that have been referred to the genus.) Dikelocephalus Owen, Beecher, 1897, American Journ. Sci., 4th ser.. Vol. 3, p. 192. (Classifies Dikelocephalus as the type of a subfamily of the Olenidse to be known as Dikelocephalinse. ^ Under the rule that, "The original orthography of the name is to be rigidly preserved unless a typographical error is evident," Owen's spelling of Dikelocephalus is followed. From Gr. (VinMa, a mattock or two-pronged hoe, and ''f'/'"'^''/, head. Z^i/tr/Gi.-r/'/za/rt.y has been called " shovel-head " (Chamberlin, 1883, Geol. Wisconsin, 1873-79, Vol. i, p. 131). 364 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 Dicellocepfialus Owen, Berkey, 1898, American Geol., Vol. 21, p. 290. (Dis- cusses forms related to D. misa Hall.) Generic description.—General form, a broad ellipse, moderately convex with pleural lobes more or less flattened, cephalon transverse ; genal angles extended into spine : cranidium roughly subquadrangu- lar in outline, with narrow fixed cheeks and strong palpebral lobes posterior to the rounded outer rim of the palpebral lobes extending • across the fixed cheeks as narrow ocular ridges. Glabella subquad- rangular in outline, and narrowing slightly towards its broadly rounded front ; posterior furrow strong and extending across the glabella ; second furrow indicated by a pair of short side furrows ; a third furrow is indicated ; strong flattened occipital ring. Facial sutures as shown by figures i, 2, and 5, plate 61. Thorax with probably twelve segments as in the closely related genus Saukia (pi. 65). Axial lobe convex; pleural lobes depressed and with each segment having a narrow, oblique furrow that begins near the inner anterior margin and terminates well out and near the posterior margin of the backward curving more or less bluntly pointed extremity. Pygidium transverse, large and with a strong central axis that ter- minates within a broad flattened border: it is marked by clearly defined transverse rings that extend out as the pleural lobes and broad border. The margin may or may not have two short postero- lateral spines. Surface with fine irregular more or less inosculating lines and, on some species, small granules over the glabella and median axis of the thorax and pygidium. It is punctate in D. hartti and D. texanus, the only two species in which the structure of the test is preserved. Some of the species of Dikelocephalus attain a large size. Speci- mens of the cephalon of D. minnesotensis in the collection of the United States National Museum have a length of 9 cm. and a width of 24 cm. Pygidia occur 9.5 cm. in length, 18 cm. in width, and a thoracic segment has a length of 16 cm. Dikelocephalus vanhornei (pi. 62) is also a large species. Genotype.—Dikelocephalus minnesotensis Owen, 1852, Stratigraphic range.—Upper beds of Upper Cambrian. Geographic distribution.—Upper Mississippi Valley in western Wisconsin and eastern Minnesota, also in central Texas, Nevada and Montana. About the Adirondack Mountains of New York, in Sara- toga and Franklin Counties and in central British Columbia. There are many references in literature to the occurrence of Dikelocephalus in various parts of America and in foreign countries, but with the NO. 13 DIKELOCEPHALUS AND OTHER GENERA 365 limitations now given the genus, it is restricted to the areas mentioned above. It is quite probable that with more thorough collecting, it will be found along the front range of the Rocky Alountains. It does not occur in the St. Lawrence Valley of Canada, but frag- ments of what may be a species of the genus occur in the Champlain Valley in Franklin County, northwestern Vermont, both in the Upper Cambrian limestone (Locality 87) and the superjacent limestone conglomerate (Locality 162). Diuiensions.—This genus includes the largest species of the Dikelo- cephalinge. One cranidium has a length of 9 cm. and width of 9 cm. at the palpebral lobes. If to this were added the proportional wide free cheeks, the width of the cephalon at its posterior margin would be 24 cm. A pygidium has a width of 18 cm. with length of 9.5 cm. A fragment of a large thoracic segment, preserving the pleural lobe has a length of 18 cm. with a longitudinal width of 1.5 cm. On the basis of the above parts an entire trilobite of this genus evi- dently existed 32 cm. in length with a width of 24 cm. Observations.—The earliest illustrations of the genotype of Dikelo- ccphalus, D. minncsotensis, are on a plate accompanying a report by' Dr. David Dale Owen, published in 1848.^ The plate faces page 58 of the report and the specimens are referred to the genus Asaphus. These include the cranidium and pygidium of a large trilobite that was in 1852 placed under the genus Dikelocephaius. Dr. Owen (1852) did not have any entire specimens, but from the resemblance of fragments of Dikelocephaius to Ogygia he compared the genus with the latter and thought it probable that the number of thoracic segments was eight as in Ogygia. He described, illustrated, and named five species, D. minnesoteiisis, D. pepinensis (=Saukia), D. miniscaensis (=Ptychaspis), D. granulosus (=Ptychaspis), and D. ioweiisis (=CrepicephalHs). Dr. E. Billings (1869) noted that he thought the doublure beneath the head of Dikelocephaius was continuous and was not cut by the facial suture. He referred several new species to the genus, D. niag- niHcus {=^ Apatokephahis ff), D. planifrons (= Anomocare) , D. belli {^^ Anomocarella), D. ozvcni {=^ Anomocare) , D. megalops (:= Anomocarella f), D. cristatus (= Ptychaspis). Dr. James Hall reviewed the genus in 1863 and referred three new species to it, D. spiniger (=^ Saukia), D. inisa (= Conokephalina), D. osceola (= Osceolia), and illustrated them from fragmentary ^ Report of a Geological Reconnaissance of the Chippewa Land District of Wisconsin, etc. Senate Doc. Exec. No. 57, 30th Congress, ist Session, 1848, p. 15, pi. 7, figs. 2, 3. 366 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 specimens. Dr. Owen's species, D. granulosus and D. miniscaensis. were placed in the genus Ptychaspis, and D. ioivensis under Cono- cephalites. In a review of Hall's work of 1863 in the American Journal of Science and Arts, the writer (probably James D. Dana) calls attention to the spelling of the name Dikelocephalus and states that the true orthography is Diccllocephahis. In 1866 Mr. J. W. Salter gave a very brief interpretation of Dikelo- cephalus and referred four species to it: Dikelocephalus (Centro- pleiira ?) fiirca {^= Dikelokephalina Brogger ??), Dikelocephalus celticns (= Distorted pygidia, genus ?), D. ? {Centropleura ?) dis- cordalus (= Perhaps Anomocare ?), D. ? ( Centropleum f) sp. (= Anomocare ?). Messrs. Hall and Whitfield (1877) mention the genus in connec- tion with the reference of two forms of pygidium of three species to it. The first, D. bilobatus, has the generic name Pterocephalus bracketed with it in the description of the plate, but it is probably a species of Anomocare. The other two species, D. multicinctus and D. Hahellifcr may be referred to Apatokephalus ? {=^ Brogger, 1897). In 1878 Prof. R. P. Whitfield noted the occurrence of specimens of trilobites preserving their natural convexity that he referred to " Dikellocephalus," as D. harabucnsis ( = Platycolpus) and D. eatoni ( =z Platycolpus) . This matter was reprinted in 1882 with illustra- tions of the species. Dr. W. Dames (1883, pp. 5, 6) calls attention to the confusion existing among the species referred to " Dikellocephalus " and sug- gests the establishing of a new genus for Owen's D. pepinensis. He comments favorably on Hall's references, but calls attention to the less careful work of Billings. Dr. G. F. Matthew (1893) attempted in a general manner to discuss the value of the generic reference of the many species that had been placed under Dikelocephalus by authors and to draw con- clusions on the supposed stratigraphic position of the genus. He concluded that in America it was strictly a Cambrian genus, and in Europe Ordovician. In 1896 Dr. Brogger followed up a previous suggestion that he had made and placed several species that had been referred to Dikelo- cephalus under the new genera Dikelokephalina, Conokephalina, and Apatokephalus. Dr. Beecher (1897) constituted the subfamily Dikelocephalinse to include Dikelocephalus and allied genera. NO. 13 DIKELOCEPHALUS AND OTHER GENERA 367 In 1913, Dr. p. E. Raymond proposed the genus Platycolpus and referred Whitfield's species Dikelocephalus barabuensis and D. catoni to it.^ The species now referred to the genus as restricted are : Dikelocephalus minnesotensis Owen (pis. 60, 61, 62, 65) Dikelocephalus minnesotensis van undt. (pi. 61, fig. 4) Dikelocephalus ? dalyi Walcott (pi. 64, figs, i-s) Dikelocephalus hartti (Walcott) (pi. 63, figs. 1-7, ya) Dikelocephalus ? limbatus Hall (pi. 65, figs. 5-8) Dikelocephalus texanus Walcott (pi. 65, fig. 4) Dikelocephalus ? tribulis Walcott (pi. 63, figs. 8-10, loa) Dikelocephalus vanhornei Walcott (pi. 62, figs. 1-3) Dikelocephalus sp. undt." (loc. 151) DIKELOCEPHALUS ? DALYI, new species Plate 64, figs. 1-5 This fine species is founded on fragments of a large trilobite that include the cranidium, portions of thoracic segments and nearly entire pygidia which occur in limestone nodules embedded in a calcareous shale. The smaller cranidia have the general outline of some of the species of Anomocare and Anomocarella from the Chinese Cambrian/ but the larger specimens have the broad, flattened frontal limb of Dikelo- cephalus. (Compare fig. 2, pi. 64, and fig. 5, pi. 61.) The palpebral lobe of D. dalyi is shorter than in typical Dikelocephalus, in this respect resembling some species of Anomocare, but not the typical species, Anomocare Iceve Angelin. The glabella is also much like that of Anomocare, but it might be included under Dikelocephalus by its outline and strong occipital ftirrow and long posterior glabella fur- rows. The associated free cheek might be referred to either genus a.i it has the general characters of each. The fragments of the thoracic segments are similar to correspond- ing parts of the thoracic segments of Dikelocephalus and, to a less degree, of Anomocare. The associated pygidia are essentially the same as the pygidium of Dikelocephalus hartti (pi. 63) and D. minnesotensis, with the excep- tion of not having the two marginal spines of the latter species. Dikelocephalus ? dalyi attains a much larger size than any known species of Anomocare, in this being comparable with Dikelocephalus. * Geol. Survey Canada, Victoria Mem. Mus., 1913, Bull. 1, pp. 63, 64. ^ See footnote ^ p. 391, this paper. ' Research in China, Vol. 3, Carnegie Institution of Washington, Pub. No. 54, 1913, The Cambrian Faunas of China, pis. 18 and ig. 368 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 Fragments of the pygidiuni indicate a width of 20 cm. at the anterior margin, which is about twice the size of the pygidium of D. vanhornei represented by figure 3, plate 62. The surface is marked by fine, raised, more or less irregular lines or sharp ridges that are subparallel to the outer margin of the border of the cephalon and pygidium and to the margins of the thoracic segments. These lines also probably occur on the glabella. Punctae similar to those of the test of Dikelocephalus are indicated. This species appears to indicate a genus intermediate in character between Dikelocephalus and Anojiwcare. In the absence of good specimens it is referred tentatively to Dikelocephalus. The only associated species is Illccnurus elongatus n. sp. The specific name is given in recognition of the discovery of the species by Dr. Reginald A. Daly. Formation and locality.—Upper Cambrian: (3466) limestone nodules in calcareous shales in rock cut on Canadian Pacific Railway, 54.5 miles (87.2 km.) west of Field, and 2 miles (3.2 km.) west of Donald Station, British Columbia, Canada (R. A. Daly, 1912). DIKELOCEPHALUS HARTTI (Walcott) Plate 63, figs. 1-7, ja Conoccphalites hartti Walcott, 1879, Thirty-second Ann. Rept. New York State Mus., p. 130. (Original description of species.) Dicelloccphalus hartti (Walcott), 1886, Bull. U. S. Geol. Survey, No. 30, p. 21. (Name used in lists of species.) Dicellocephalus hartti (Walcott), Lesley, 1889, Geol. Surv. Pennsylvania, Rept. P4, Dictionary of Fossils, Vol. i, p. 199. (Text figures reproduced from drawings sent him by Walcott.) Dicellocephalus hartti (Walcott), 1912, Smithsonian Misc. Coll., Vol. 57, No. 9, p. 2y2i, pl- 44, figs. 1-7, Ja. (Describes, illustrates, and comments on species.) A description with comments on this species has been recently pub- lished (Walcott, 1912). The only additional information is to note the occurrence of several pygidia that appear to be identical with those illustrated on plate 63, figures 6, 7 of this species, in the upper layer of the Potsdam formation on Marble River, north of the Adi- rondack Mountains in New York. Formation and locality.—Upper Cambrian : Hoyt formation ; (76) arenaceous limestone at Hoyts quarry, 4 miles (6.4 km.) west of Saratoga Springs, and (76a) in a railroad quarry, i mile (1.6 km.) north of Saratoga Springs, both in Saratoga County (C. D. Walcott NO. 13 DIKELOCEPHALUS AND OTHER GENERA 369 and Cooper Curtice, 1883) ; also (m), at the top of the Potsdam sandstone on Marble River, i mile (1.6 km.) south of Chateaugay, Franklin County (C. D. Walcott, 1886), all in New York. DIKELOCEPHALUS ? LIMBATUS Hall Plate 65, figs. 5-8 Dikelocephalus tiiinnesotensis var. liiiibatus Hall, 1863, Sixteenth Ann. Rept. New York State Cab. Nat. Hist., p. 141, pi. 9, fig. 12. (Describes and illustrates anterior portion of a cranidium.) Diccllocephalus minnesoteiisis Owen, WI^XHF.LL, 1864, American Journ. Sci., 2d ser.. Vol. S7' P- 229. (Remarks on occurrence of a species of Diccllo- cephalus doubtfully referred to this species.) Dikelocephalus vii)uiesotciisis var. limbatus Hall, 1867, Trans. Albany Inst., Vol. 5, p. 121, pi. 4, fig. 12. (Reprint of paper of 1863.) This very interesting species is represented by several fragments from locality 78 where the cranidium represented by figure 6 is asso- ciated with the pygidium represented by figure 7. The broad, slightly concave, frontal limb and subquadrilateral glabella bring the species close to Dikelocephalus as does the associated pygidivun. The latter has the relatively short axial lobe and broad flattened border of the pygidia of D. minnesotensis, but it dififers in the details of the furrows on the pleural lobes and in the absence of spines on the margin. Dr. James Hall considered the fragment that he described as a variety of D. minnesotensis^ but with the specimens now available for study the varietal name limhatus is used as the specific name. Formation and locality.—Upper Cambrian : St. Lawrence forma- tion; (78) quarry near St. Croix River, in suburbs of Osceola, Polk County (L. C. Wooster, 1883) ; (78b) 50 feet (15.2 m.) above St. Croix River, near the landing at Osceola, Polk County (Cooper Curtice, 1884), and (134a) in a quarry i mile (1.6 km.) southeast of the county court house, in Menomonie, Dunn County (Chas. Schuchert, 1893), all in Wisconsin. A number of specimens of the pygidium and free cheeks of a species closely related to D. ? limbatus occur in the Jordan sandstone (8ib), near Devils Lake, Sauk County (Cooper Curtice, 1884). These are the forms described by Dr. Alexander Winchell. One of the pygidia is illustrated by figure 8, plate 65. DIKELOCEPHALUS MINNESOTENSIS Owen Plate 60, figs. 1-8; plate 61, figs. 1-3, 5-7; plate 62, figs. 4-6; plate 66, fig. i. Asaphus Owen, 1848, Rept. Geol. Reconnaissance, Chippewa Land District, Senate Doc, Exec. No. 57, 30th Congress, p. 15, pi. 7, figs. 2, 3. (Illus- trates cranidium and pygidium under name Asaphus.) 3/0 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 Dikeloccplialus ininiiesotensis Owen, 1852, Rept. Geol. Survey Wis., Iowa, and Minn., p. 574, pi. i, figs, i, 2; pi. la, figs. 3, 6. (Description and illustrations of species. Fig. 10, pi. i, is now referred to D. crassimar- ginatus.) Ogygia minnesoteiisis (Owen), Chapman, 1856, Canadian Journ., new ser., Vol. I, p. 275. (Refers species to Ogygia.) Dikelocepfialus minncsotensis Owen, ^Mackie, 1859, The Geologist (Lon- don), Vol. 2, p. 189, fig. 4. (Text figure of Owen's restoration of the species.) Dikclocephalus minnesoteiisis Owen, Hall, 1862, Rept. Geol. Survey Wis- consin, Vol. I, p. 22, figs. I, 2. (Illustrates a cranidium and a pygidium.) Dikelocephalus minnesoteiisis Owen, Hall, 1863, Rept. Geol. Survey Wiscon- sin, p. 138, pi. 9, figs. 5-10; pi. 10, figs. 10-12; pi. II, figs. I, 3, and 4, (Species described and illustrated from fragmentary specimens.) Dikelocephalus minnesotensis Owen, Hall, 1867, Trans. Albany Inst., Vol. 5, p. 117, pi. 4, figs. 5-10; pi. 5, figs. 10-12; pi. 6, figs. I, 3, 4. (Reprint of paper of 1863.) Dikellocephalus minnesotensis Owen, Whitfield, 18S2, Geol. Wisconsin, 1873-79, Vol. 4, p. 187, pi. 3, fig. I. (Describes species and illustrates a pygidium.) Dicelloceph'alus minnesotensis Owen, W^alcott, 1886, Bull. U. S. Geol. Sur- vey, No. 30, p. 35, par. 66. (Notes occurrence of species in Highland Range, Nevada.) Dicellocephahis minnesotensis Owen, Lesley. i88q, Geol. Survey Pa.. Rept. P. 4, Dictionary of Fossils, Vol. i, p. 198, fig. i. (Reproduces figures from Owen.) Dicellocephalus minnesotensis Owen, Miller, 1889, North American Geol. and Pal., p. 544, text fig. 999. (Restored figure of entire dorsal shield.) Dikelocephalus minnesotensis Owen ( ?), Walcott, 1891, Bull. Geol. Survey, No. 81, p. 235. (Notes probable occurrence of species in Texas in giving names of fossils.) Dikelocephalus minnesotensis Owen, S.\rdeson, 1896, Bull. ^Minnesota Acad. Nat. Sci., Vol. 4, p. 95. (Mentions occurrence of species at localities in ]\Iinnesota.) Dr. James Hall in 1863 published a detailed description of all that was known to him of the species, and practically nothing has been added since. No entire specimens of the dorsal shield are known to me. It is probable that there were 12 segments in the thorax as in Saiikia, but this is uncertain. The species is confined to the Mississippi valley as far as now known, with the possible exception of a locality in Lincoln County, Nevada, where fragm.ents associated with Saiikia pepinensis appear to indicate its presence. Formation and locality.—Upper Cambrian : St. Lawrence for- mation ; (85) at Prairie du Sac, Sauk County (Cooper Curtice, 1884). and (86) at Van Ness quarry, Gibraltar Blufif, Lodi, Colum- bia County (L. C. Wooster, 1883 ; Cooper Curtice, 1884), both in Wis- NO. 13 DIKELOCEPHALUS AND OTHER GENERA 37I consin ; also. (86b) hilltop, north end of city of Lansing, Allam- akee County, Iowa ( P. Bartsch, 191 2) . Also from locality (83'), an upper horizon of the St. Lawrence formation near Trempealeau, Trempealeau County (Cooper Curtice and G. H. Squiers, 1884; Chas. Schuchert, 1893) ; (113) at La Grange Mountain (or Barn Blufif), near Red Wing, Goodhue County (Cooper Curtice, 1884) '• (^5^) bank of St. Croix River. Stillwater. \\'ashington County, all in ]\Iinnesota. Doubtful identifications.—From the upper beds of the old " St. Croix sandstone," or St. Lawrence formation. (3390 Among fragments from the Copper Cambrian sandstones at ]\linneiska, Minnesota, on the Mississippi River, there is one of a large thoracic segment that may belong to this or an allied species. At Localities 78 and 78b, Osceola, Wisconsin, a somewhat similar segment and a fragment of a large cranidium (pi. 62, figs. 4, 6) indi- cate that a large species is present. Better specimens may prove that the material belongs to a distinct and undescribed species or to Dikelo- ccphalus limbatus. ( 78) Lpper Cambrian : St. Lawrence sandstone series ; quarry near St. Croix River, in suburbs of Osceola, Polk County (L. C. Wooster, 1883), and (78b) 50 feet (15.2 m.) above St. Croix River, near the landing at Osceola, Polk County (Cooper Curtice, 1884) , both in Wisconsin ; also (339f ) near Minneiska (Miniska) , on Mississippi River, near the line between Wabasha and Winona counties, Minnesota (F. M. Brown). DIKELOCEPHALUS MINNESOTENSIS var. Plate 61, fig. 4 A variety of D. minnesotensis occurs at La Grange mountain (Locality 113) that is represented by the pygidium illustrated by figure 4, plate 61. This has four rings on the median lobe and four segments outlined on the pleural lobes, while D. minnesotensis has seven or eight rings on the median lobe and eight or ten segments outlined on the pleural lobes (pi. 61, fig. 6). A second pygidium possibly of this variety comes from Osceola at a horizon higher as indicated by the associated fauna. Formation and locality.—Upper Cambrian : St. Lawrence forma- tion ; (113) sandstone at La Grange Mountain (or Barn Blufif), near Red Wing, Goodhue County, Minnesota (Cooper Curtice. 1884), and ( 78b) 50 feet ( 15.2 m.) above the St. Croix River, near the land- ing at Osceola, Polk County, Wisconsin (Cooper Curtice. 1884). 372 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 5/ DIKELOCEPHALUS TEXANUS, new species Plate 65, fig. 4 Of this species only the fragment of the posterior half of the crani- dium illustrated has been seen. This indicates a large form compar- able with Dikelocephalus minnesotensis. It differs from that in hav- ing the palpebral lobe farther forward, and from D. vanhornei in having the palpebral lobe nearer the glabella. With better specimens probably other differences might be found. The outer test has been exfoliated, but from the impression of the inner surface it is evident that it was marked by rather strong, nar- row, irregular lines. Formation and locality.—Upper Cambrian: (70a) Wilberns for- mation, Baldy Mountain, near Morgans Creek, 8 miles (12.8 km.) northwest of Burnet, Burnet County, Texas (C. D. Walcott, 1884). Fragments of a large trilobite that may be a species of Dikeloceph- alus occur in the lower portion of the Arbuckle limestone of Okla- homa (i2g), 150 miles (240 km.) north of the locality (70a) where D. texanus occurs. Unfortunately there is not sufficient material by which to compare the cranidia. The fragments at both localities indi- cate a large species comparable with D. minnesotensis. DIKELOCEPHALUS ? TRIBULIS Walcott Plate 63, figs. 8-10. loa Dicellocephalus tribulis Walcott, IQ12, Smithsonian Miscellaneous Coll., Vol. 57, No. 9, p. 274, pi. 44, figs. 8, 8a. (Illustrates and comments on species.) With only imperfect specimens of the cranidium and a fragment of a pygidium doubtfully referred to the species, it is difficult to make a satisfactory generic reference. The position of the palpebral lobes and the slightly concave frontal limb suggest Conokephalina misa (Hall) (pi. 68, figs, i, 2), while the form of the glabella is much like that of Dikelocephalus hartti. It may be that with the discovery of entire specimens of this species and Conokephalina misa the two will be found to be congeneric and an intermediate form between Dikelocephalus and Saukia. The largest specimen of the cranidium in the collection has a length of 16 mm. Formation and locality.—Upper Cambrian: (76) Hoyt formation; arenaceous limestone at Hoyts quarry, 4 miles (6.4 km.) west of Sara- toga Springs, Saratoga County, New York (C. D. Walcott and Cooper Curtice, 1883). NO. 13 DIKELOCEPHALUS AND OTHER GFNERA 373 DIKELOCEPHALUS VANHORNEI, new species Plate 62, figs. 1-3 This is a fine, large species of which we have for study the cranidium thoracic segments, and pygidium. The cranidium is much Hke that of D. inhinesoicnsis. It differs in having a proportionaUy shorter glabella and wider fixed cheeks. The thoracic segments are of the same type, but the pygidium is quite unlike that of D. tninnc- sotensis. It is more transverse and has a larger axial lobe and a smoother margin unbroken by spines. The type specimen of the cranidium (fig. i) has a length of 5.5 cm. and an associated pygidium (fig. 3) has a length of 4.6 cm. and width of 9.8 cm. The specimens occur as casts in a fine-grained, yellowish gray, shaly sandstone and show only a few traces of a roughened surface on the cranidium, and of fine raised, irregular lines on the flattened borders of the pygidium. The specific name is given in recognition of the early work of Sir William Van Home, who, as a young man, formed a collection of fossils in Wisconsin, which he subsequently presented to the Museum of McGill University, Montreal, Canada. Formation and locality.—Upper Cambrian : St. Lawrence for- mation ; (346d) railroad dam at Hoka, Houston County, Minnesota. Type specimens in Walker Museum, University of Chicago. Pal. Coll. No. 14393. Plastotype No. 346d, U. S. Nat. Mus., Cat. No. 58608. While the above was in galley proof I received from Mr. W. A. Finkelnburg, of Winona, Minnesota, specimens of the pygidium of this species which were found in the bluffs near Winona. Genus SAUKIA, new genus General form elongate oval ; moderately convex. Cephalon trans- versely semi-ovate with genal angles extended backward in strong spines. Axial and pleural lobes strongly outlined. Marginal border slightly rounded or nearly flat and merging into genal spines ; poste- rior margin with a narrow, rounded, well-defined rim ; occipital ring strong, nearly transverse. Glabella subquadrangular ; usually narrowing opposite the palpe- bral lobes by slight incurving of its sides ; frontal margin broadly rounded ; occipital furrow strongly defined ; posterior glabellar fur- row strong, second furrow less pronounced than the first, and not con- 374 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 5/ nected at the center ; third furrow usually faintly defined and repre- sented by a short furrow on each side of the glabella that extends directly inward instead of slightly backward as in the first and second glabellar furrows. Free cheeks rather large and convex. Palpebral lobe prominent, about one-half the length of the glabella ; marked by a strong intramarginal furrow ; anterior margin a little in advance of the transverse center of the glabella. Eye lobe narrow. The facial sutures cut the posterior margin well out toward the genal spine and curve quickly inward to the posterior margin of the eye, outlining the narrow postero-lateral limbs of the cranidium ; arching outward around the palpebral lobes they curve slightly out- ward and then inward so as to cut the front margin on a longitudinal line passing through the outer margin of the palpebral lobe. Thorax with 12 segments. Axial lobe convex with each segment gently rounded and with a very faint longitudinal furrow on each side that serves to define a slight swelling at the end of each segment. Pleural lobes of nearly uniform width throughout and with each segment terminating in a short falcate end ; pleural furrows narrow, deep, and crossing the pleurae obliquely from the anterior inner end to the posterior third of the falcate terminal section. Pygidium transversely and approximately semicircular with the anterior margin arched forward ; strongly trilobed. Axial lobe con- vex, with four to eight transverse segments. Pleural lobes with flat- tened margin that is usually free from pleural and segmental fur- rows ; surface marked by segmental lines and narrow pleural furrows of the same general character as the pleural furrows of the thoracic segments. Surface pustulose as in Saiikia lodensis (pi. 65, figs, i, 2) to minutely granulose as in Saukia pepinensis (pi. 67). Dimensions.—The largest specimen of the typical species is illus- trated by figure i, plate 65. None of the species referred to Saukia approaches in size Dikelocephalus minncsotcnsis (pi. 60). Genotype.—Dikelocephahts lodensis Whitfield (pi. 65, fig. i). The genus Saukia ' is proposed for a group of trilobites that have heretofore been referred to Dikelocephalus. It differs from the latter in having a comparatively narrow frontal limb to the cephalon ; a pro- portionately longer glabella that may be narrowed opposite the pal- pebral lobes and slightly expanded anteriorly and that is more elon- gate proportionally than in Dikelocephalus. As far as known the ^ Indian name Sauk applied to Sauk County, Wisconsin, in which localities specimens of Saukia lodensis occur. NO. 13 DIKELOCEPHALUS AND OTHER GENERA 375 thoracic segments of the two genera are similar. The pygidium of Saukia is less expanded and more elongate than that of D ikch- eephalus. Saiikia differs from Osceolia (pi. 68, figs. 4-10) in having a concave instead of a depressed convex anterior margin to the cephalon, and a rounded, smooth margined pygidium. It differs from CalvineUa (pi. 69, figs. 1-5) in form of glabella, absence of a strong occipital spine, and proportionately less trans- verse pygidium. These characters may possibly be accompanied by other differences in the thorax not at present known. The species now referred to the genus are : Saukia coloradocnsis Walcott (text figs. 13-16, p. 376) Saukia crassimarginata (Whitfield) (pis. 61, 65, 66) Saukia falla.v Walcott (pi. 67, figs. 21, 21a, 22, 22a) Saukia junia Walcott (text fig. 17, p. 378) Saukia ?? Icptcrnarum (Wiman) Saukia leucosia Walcott (pi. 67, figs. 14-17) Saukia lodcnsis (Whitfield) (pi. 65, figs. 1-3) Saukia marica (Walcott) (pi. 64, figs. 6, 6fl) Saukia pepinensis (Owen) (pi. 67, figs. 1-13) Saukia pyrene Walcott (pi. 6y, figs. 18-20) Saukia rustica Walcott (text figs. 18, 19, p. 383) Saukia stosei Walcott (pi. 69, figs. 3-5) Saukia zvardi Walcott (pi. 69, figs. 1-2) Stratigraphic range.—Found in both the upper and lower zones of the St. Lawrence formation and Lower Ozarkian. Geographic distribution.—Several of the species are found in the upper Mississippi valley in Wisconsin and eastern Minnesota. Saukia pepinensis occurs in central eastern Nevada and 6*. falla.v is from central Texas. Saukia eoloradoensis occurs at Quandary Peak, Summit Coutity, Colorado. Two species, S. stosei and S. wardi, are from the Appalachian Province in southwestern Pennsylvania and western Virginia. Observations.—The species referred to Saukia fall into two groups. The first, characterized by 6". lodeusis, S. eoloradoensis, and .S". crassi- marginata, which most nearly approach Dikeloccphalus, except in the character of the frontal limb and margin. The second, character- ized by 6^. pepinensis and its allies, 6*. leucosia, S. pyrene, S. stosei and 5. zvardi, which appear to be intermediate between Dikeloccphalus and forms referred to Anomocare, but with a leaning towards Dikelo- ccphalus. With the discovery of entire specimens of the several species it may be that a rearrangement of the generic references of the several species now placed under Saukia will be necessary. 3 3/6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 SAUKIA COLORADOENSIS, new species Text figures 13-16 Dicellocephaliis minnesotensis ?, 1886, Monogr. U. S. Geol. Survey, Vol. 12, p. 60. (Name mentioned in text. Label with specimens states that the identification was by R. P. Whitfield.) This species is represented by fragmentary specimens of the cranidium, free cheeks, thoracic segments, and pygidium. At first I referred it to Saukia crassunarginata, but on working the cra- nidium and pygidium free from the covering matrix it was found to differ. The frontal hmb is less convex and is marked by a slight Saukia coloradoensis, new species Fig. 13. (X 2.) Cranidium flattened in shale. Postero-lateral limbs re- stored. U. S. National Museum, Catalogue No. 60673. Fig. 14. (Natural size.) Large free cheek with outline partly restored. U. S. National Museum, Catalogue No. 60674. Fig. 15. (Natural size.) Pygidium with outline restored. U. S. National Museum, Catalogue No. 60675. Fig. 16. (Natural size.) Matrix of pygidium with outline partly restored. U. S. National Museum Catalogue No. 60676. NO. 13 DIKELOCEPHALUS AND OTHER GENERA 377 transverse furrow that serves to outline a narrow flattened border- ing rim. The associated pygidium has a longer axial lobe. The specimens are all ^ from locality 20b, Upper Cambrian ; about I mile (1.6 km.) above Monte Cristo Mine, Quandary Peak, Sum- mit County, Colorado (Whitman Cross, collector, 1880). This is a large species and it may be the largest one of the genus. It is also of special interest owing to its geographic position. A careful search in the Upper Cambrian of the Leadville region may result in finding good specimens of this species and, of still greater importance, the fauna that accompanied the invasion of the Upper Cambrian sea in this region. Formation and locality.—Upper Cambrian: (20b) about i mile (1.6 km.) above Monte Cristo Mine, Quandary Peak, Summit County, Colorado (Whitman Cross, collector, 1880). SAUKIA CRASSIMARGINATA (Whitfield) Plate 61, fig. 8; plate 65, figs. 9, 10; plate 66, figs. 2-5, 5a Dikelocephalus {minnesotensis ?) Owen, 1852 (in part), Rept. Geol. Survey Wis., Iowa, and Minn., p. 574, Tab. i. fig. 10. (Figure of cranidium doubtfully referred to D. minnesotensis.) Dikelocephalus minnesotensis var. Hall, 1863 (in part), Sixteenth Ann. Rept. New York State Cab. Nat. Hist., p. 141, pi. 9, fig. 11 ; pi. 10, fig. 9; pi. II, fig. 2. (Two cranidia described and illustrated. Free cheek ten- tatively referred to D. pepinensis.) Dikelocephalus viinnesotensis var. H.'\ll, 1867, Trans. Albany Inst., Vol. 5, pi. 4, fig. II ; pi. S, fig. 9. (Reprint of figures of 1863.) Dikellocephaliis crassiniarginatus Whitfield, 1882^ Geol. Wisconsin, Vol. 4, p. 344, pi. 27, fig. 14. (Describes and illustrates free cheek as type of species.) Dicellocephalus Chamberlin, 1883, Geol. Wisconsin (Survey of 1873- 1879), Vol. I, p. 129, text fig. 15. (Illustrates a nearly entire specimen from Prairie du Sac that is evidently this species.) This fine species is generically related to Saiikia lodensis (pi. 65. fig. i). It differs specifically from it in having a broader border to the cephalon and pygidium, broader fixed cheeks, and smooth surface over the entire dorsal test. It also attains a larger size. An entire specimen in the collection of the United States National Museum has a length of 9.7 cm., with a width of 6.8 cm. at the back of the cephalon. Other proportions are shown by figure 2, plate 66. Several pygidia (pi. 65, fig. 9) resembling the pygidium of this spe- cies occur in the coarser Jordan? sandstone (81, 8ib) near Devils Lake. The specific identification must remain doubtful until speci- ^ See also page 378, second species under Sattkia fallax. 378 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 mens of the cephalon are found. A similar pygidium occurs in the upper beds of sandstone near Trempealeau: (83') Upper Cambrian: St. Lawrence formation ; near Trempealeau, Trempealeau County, Wisconsin (Chas. Schuchert, 1893). The western representative of this species is Saukia coloradoensis. Formation and locality.—Upper Cambrian : St. Lawrence series ; (85) at Prairie du Sac, Sauk County (Cooper Curtice, 1884) ; also (85X) beds near Mazomanie, Dane County (Chas. Schuchert, 1893) ; (78b) 50 feet (15.2 m.) above St. Croix River, near the landing at Osceola, Polk County (Cooper Curtice, 1884) ; and doubt- fully (81) Jordan sandstone series, i mile (1.6 km.) east-northeast of Devils Lake, Sauk County (L. C. Wooster, 1883) ; (8ib) Jordan? sandstone, near Devils Lake, Sauk County (Cooper Curtice, 1884), all in Wisconsin. SAUKIA FALLAX, new species Plate 67, figs. 21, 2ia, 22, 22a This species is represented by specimens of the cranidium. The form of the glabella and frontal rim relate it to S. pcpinensis, S. leu- cosia, and 6". pyrcne, all of which are illustrated on the same plate. It differs from the nearly related 6". pyrene and 6^. zvardi (pi. 69, fi§'- 3) by having a slightly tapering glabella and smoother surface. Formation and locality.—Upper Cambrian: (70a) Wilberns for- mation, Baldy Mountain, near Morgans Creek, 8 miles (12.8 km.) northwest of Burnet, Burnet County, Texas (C. D. Walcott, 1884). A second species from Texas, not unlike Saukia coloradoensis (p. 376), is shown by fragments occurring in a shale from San Saba County. SAUKIA JUNIA, new species Text figure 17 This is a species allied to both Saukia crassimarginata (pi. 66) and 6^. pcpinensis (pi. 67). It is represented by a broken cranidium 17 Saukia junia, new species Fig. 17. (Natural size.) Type specimen in limestone and side outline. U. S. National Museum, Catalogue No. 60677. NO. 13 DIKELOCEPHALUS AND OTHER GENERA 379 22 mm. in length. The frontal limb is proportionally longer than that of either of the above species, and there is a peculiar flattening of the frontal border in advance of the glabella with a narrow trans- verse ridge outlining the broad, downward sloping frontal margin. The glabella expands a little anteriorly. Surface of test apparently smooth. Formation and locality.—Upper Cambrian: (i2g: 50 feet above I2J) Arbuckle limestone (lower part) ; Wichita jNIountains, south side about 8 miles (12.8 km.) west of Fort Sill and in a small hill 2 miles (3.2 km.) southwest of Signal Mountain, Comanche County, Oklahoma. Fossil horizon No. 3 of E. O. Ulrich, 100 feet (30.4 m.) from base of hill. Collected October 9, 1901. SAUKIA ? ? LEPTJENARUM (Wiman) Dicellocephalus ? leptcenarum Wiman, 1907, Arkiv for Zoologi, Bd. 3, No. 24, p. 5, pi. 2, figs. 1-3. (Described and illustrated as a new species.) This species is founded on a small pygidium that resembles the pygidium of Saiikia leucosia (pi. 67, figs. 13, 13a). It is possible but not probable that the pygidium belongs to a species of Sankia. Formation and locality.—Ordovician : Leptcciia limestone, west Baltic region, Sweden. SAUKIA LEUCOSIA, new species Plate 67, figs. 14-170 This fine species is represented by specimens of the cranidium, free cheeks, and possibly the pygidium. It differs from the associated Saukia pyrene (pi. 67, figs. 18-20) by having a broad, rounded frontal limb, a character that serves also to distinguish it from S. pepinensis (pi. 6y, figs. 1-5) and S. stosei (pi. 69, fig. 3). Formation and locality.—Upper Cambrian : St. Lawrence forma- tion (78), quarry near St. Croix River, in suburbs of Osceola, Polk County, Wisconsin (L. C. Wooster, 1883) . Franconia formation (99), Minneiska (Miniska), on Mississippi River, near the line between Wabasha and Winona Counties, Minne- sota (Cooper Curtice, 1884). SAUKIA LODENSIS (Whitfield) Plate 65, figs. 1-3 Dikcllocephalus lodensis Whitfield, 1880, Ann. Rept. Wis. Geol. Survey for 1879, p. 51. (Founds species on a free cheek.) Dikellocephalus lodensis Whitfield, 1882, Geol. Wisconsin, Vol. 4, p. 188, pi. 10, fig. 14; p. 341; pi. 27, figs 12-13. (Reprints former description and illustrates free cheek, and on pi. 27, figs. 12 and 13, a nearly entire dorsal shield.) 380 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 Dicelloccphalus lodcnsis Whitfield, Chamberlin, 1883, Geol. Wisconsin, Vol. I, p. 130, text figs. 16, i6a-b. (Illustrates nearly entire specimen of dorsal shield.) The generic description of Saukia is based on this species; this with the figures on plate 65 gives a sufficiently complete conception of the species to furnish the student with the means for identifying and comparing it with other species. It differs from the other species referred to the genus by its strongly granulose surface and variations in details of form of the parts of the cephalon and pygidium. Formation and locality.—Upper Cambrian : St. Lawrence forma- tion; (85) at Prairie du Sac, Sauk County (Cooper Curtice, 1884) ; (86) at Van Ness quarry, Gibraltar Blufif, Lodi, Columbia County (L. C. Wooster, 1883 ; Cooper Curtice, 1884), both in Wisconsin. SAUKIA MARICA (Walcott) Plate 64, figs. 6, 6a Dicelloccphalus inarica Walcott, 1886, Monogr. U. S. Geol. Surv., Vol. 8, p. 44, pi. 10, fig. 13. (Described as below.) Glabella and fixed cheeks subquadrate in outline, narrowing some- what towards the front. Glabella subquadrangular and almost squarely truncate in front, which is not quite as wide as the base ; strongly convex, and marked by three pairs of furrows, the two anterior pairs but slightly depressed and very short ; the posterior pair extend obliquely inward one-third the distance across from each side, and are united by a slight transverse furrow ; occipital ring strong and elevated ; occipital furrow well defined ; dorsal furrows strongly impressed ; fixed cheeks moderately convex, narrow in front, widen- ing at the palpebral lobes, and sloping away rapidly in front, and less so back of the eye lobes ; eye lobes narrow, semicircular, and situated opposite the central portion of the glabella; frontal limb obsolete except the round, thick, marginal rim just in advance of the glabella the posterior limbs are broken away at a little distance from the dorsal furrows. Surface as seen under a strong magnifying glass, with fine inoscu- lating, flattened lines surrounding minute round or irregularly oval spaces. Observations.—This species is represented by one specimen of the cranidium. It resembles the cranidium of Saukia pyrene (pi. 6y, fig. 18) and vS". fallax (pi. 67, fig. 21), but dififers in its frontal border. It occurs in the closing epoch of the Cambrian in association with a well-marked fauna (see locality 62, p. 361) . NO. 13 DIKELOCEPHALUS AND OTHER GENERA 381 Fonnatio)! and locality.—Upper Cambrian (62) in thin layer of limestone in Dimderberg shale, in canyon immediately north of Adams Hill, Eureka District, Nevada' (C. D. Walcott, 1880). SAUKIA PEPINENSIS (Owen) Plate 67, figs. 1-13, 13a Dikelocephalns pepincnsis Owen, 1852, Reptt Geol. Surv. Wis., Iowa, and Minn., p. 574, pi. i, figs. 9, ga-h. (Describes and illustrates species.) Dikelocephalns pepincnsis Owen, Hall, 1862, Rept. Geol. Surv. Wis., Vol. i, p. 22, text figs. 3, 4. (Illustrates cranidium and pygidium.) Dikelocephalns pepincnsis Owen, Hall, 1863, Sixteenth Ann. Rept. State Cab. Nat. Hist., p. 142, pi. 9, figs. 1-4; pi. 10, figs. 14-17. (Describes in detail and illustrates species. Fig. 13 does not appear to belong with this species.) Dicelloccphalns pepincnsis Owen, Winchell, 1864, American Journ. Sci., 2d ser., Vol. 37, p. 229. (Comments on cranidium and describes an associated pygidium.) Dikcloccphalus pepincnsis Owen, H.\ll, 1867, Trans. Albany Inst., Vol. 5, p. 122, pi. 4, figs. 1-4 ; pi. 5, figs. 14-17. (Republishes text and illustrations of 1863.) Dicelloccphalns pepincnsis Owen, Chamberlin, 1883, Geol. Wisconsin, Vol. I, p. 130, figs. i6c-f, after Hall, 1863. (Copies figures of Hall with- out description.) Dicelloccphalns pepincnsis Owen, Walcott, 1886, Bull. U. S. Geol. Survey, No. 30, p. 35, paragraph 66. (Notes occurrence of species in Highland Range, Nevada.) Dikcloccphalus pepincnsis Owen, Brogger, 1897, Nyt Mag. for Naturvid., Vol. 36, p. 17s, fig. 9. (Illustrates pygidium after Hall.) This species is readily recognized by its strong, flattened frontal rim and convex compact pygidium with a narrow, slightly flattened border. The description, given by Hall in 1863, is so detailed and accurate that it does not appear necessary to attempt to add to it. Fragments of the species occur in great abundance in the shaly sandstones of the upper horizon of the St. Lawrence sandstones of Wisconsin. Comparisons with other species referred to Saiikia are given under observations on the genus. Specimens of a cranidium and a pygidium that appear to be identi- cal with those from Wisconsin occur in the Highland Range of Nevada in a limestone in association with fragments of a large trilo- bite that indicates a species which may be Dikelocephalns minnc- sotensis.^ ^ In Monograph 8 of the U. S. Geological Survey, p. 45, the locality of the type specimen is incorrectly given as just south of the Hamburg Mine. The geological horizon is correct but not the exact locality. ^ Bull. U. S. Geol. Survey, No. 30, 1886, p. 35, paragraph 66. 382 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. S7 Formation and locality.—Upper Cambrian : St. Lawrence forma- tion ; (113) at La Grange Mountain (or Barn Bluff), near Red Wing-, Goodhue County; also, (132) about 2 miles (3.2 km.) north- west of Lake City, on Lake Pepin, Wabasha County (Chas. Schu- chert, 1893), all in Minnesota. (85X) Near Mazomanie, Dane County, Wisconsin (Chas. Schu- chert, 1893). (88) Upper Cambrian : Hamburg formation (limestone), west side of Highland Range, 17 miles (27.2 km.) southwest of Pioche and 7 miles (-11.2 km.) north of Bennetts Spring, Lincoln County, Nevada (C. D. Walcott, 1887). A cranidium and free cheeks that may belong to a variety of this species occur in a friable sandstone with Dikeloccphalus cf . limhatns. Osceolia osceola (Hall) and Saukia leucosia Walcott, near Devils Lake, Wisconsin. The parts are larger than in the typical specimens and it may be that another species is indicated. Localities 81 and 8ib, Upper Cambrian : Jordan? sandstone : i mile (1.6 km.) east-northeast of Devils Lake, Sauk County, Wisconsin (L. C. Wooster, 1883 ; Cooper Curtice, 1884). ' SAUKIA PYRENE, new species Plate 67, figs. 18-20 This species is represented by numerous fragments of the dorsal test including the cranidium, free cheeks and pygidium. At first sight the cranidium was referred to the Texas form of Saukia fallax (pi. 67, fig. 21), but closer comparison showed that its glabella was pro- portionally narrower and the sides more nearly parallel. The frontal rim is of the same character in the two species. The pygidium asso- ciated with S. pyrene (fig. 20, pi. 6y) is unlike that associated with 6". fallax in Texas (figs. 21, 21a, pi. 67). Saukia pyrene differs from the associated 5^. leucosia (pi. 67, figs. 14-17) mainly in its rounded strong frontal limb. The frontal limb of S. pepinensis (pi. 67, figs. 1-5) is flattened and the glabella is propor- tionally wider than that of 6^. pyrene. Formation and locality.—Upper Cambrian : St. Lawrence forma- tion ; (78) quarry near St. Croix River, in suburbs of Osceola, Polk County, Wisconsin (L. C. Wooster, 1883). A somewhat similar form is indicated in the sandstone at Devils Lake by the presence of cranidia and free cheeks (8ib) : Jordan? sandstone; i mile (1.6 km.) east-northeast of Devils Lake, Sauk County, Wisconsin (L. C. Wooster, 1883; Cooper Curtice, 1884). NO. 13 DIKELOCEPHALUS AND OTHER GENERA 383 SAUKIA RUSTICA, new species Text figures 18-20 The cranidium of this species is much Hke that of Saukia lodcnsis (pi. 65). It differs in its proportionally larger palpebral lobes, nar- rower glabella, and exterior surface of the test. The test of 6". lodensis is covered with rather large, rounded pustules, and that of S. rustica with fine inosculating, irregular ridges that give it a roughened but not a pustulose appearance. The largest cranidium has a length of 7 mm. Small specimens 2 to 6 mm. in length show a narrowing of the glabella toward the rounded front. The associated pygidium has a smaller axial lobe than that of 5'. lodensis. 19a Saukia rustica, new species Figs. 18, i8a. (X 4-) Type specimen of cranidium and side outline. U. S. National Museum, Catalogue No. 60678. Figs. 19, 19a. (X 2.) Pygidium associated with fig. 18. U. S. National Museum, Catalogue No. 6067Q. Fig. 20. (X 6.) Small cranidium. U. S. National Museum, Catalogue No. 60680. The associated pygidium is much like that of Saukia fallax (pi. 67, fig. 21), and the cranidium is of the same general character. Eoorthis zvichitaensis Walcott and Illccnunis sp. undt. are asso- ciated with S. rustica. Formation and locality.—Upper Cambrian: (i2J: 50 feet below i2g) Arbuckle limestone (lower part) ; Wichita Mountains, south side about 8 miles ( 12.8 km.) w^est of Fort Sill and in a small hill 2 miles (3.2 km.) southwest of Signal Mountain, Comanche County, Oklahoma. Fossil horizon No. 5 of E. O. Ulrich, 50 feet from base of hill. Collected October 9, 1901. 384 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 5/ SAUKIA STOSEI, new species Plate 6g, figs. 3-5 ; pi. 70, figs. 12, 12a Dikeloccphahts hariti Stose (on authority of Walcott), 1909, U. S. Geol. Survey Geol. Atlas, U. S., Folio No. 170, p. 6. (Name mentioned in list of fossils from .Conococheague limestone.) Dikeloccphalus sp. imdt. Stose (on authority of Walcott), 1909, idem, p. 6. (Mentioned with preceding species.) This species belongs to the S. pepinensis form of Saukia, and is most nearly related to Saukia fallax (pi. 67, figs. 21, 21a), but it has a proportionately larger palpebral lobe. The associated pygidium (fig. 5, pi. 69) differs from the pygidium found with S. fallax in Texas in having a longer axial lobe, and the surface is strongly granu- lated instead of being smooth as in 5". fallax. The specific name is given in recognition of the fine work of Mr. George W. Stose, of the United States Geological Survey. Formation and locality.—Lower Ozarkian (Ulrich) : (5911 and 59 o) Conocheague limestone, about 800 feet (240 m.) above the base, that is, near the middle, of the formation in a quarry on point of spur northwest of Scotland Station, Franklin County, Pennsylvania (E. O. Ulrich ; G. W. Stose, 1901). U. S. Geol. Survey Atlas, folio No. 170. SAUKIA WARDI, new species Plate 69, figs. I, 2 This species is represented by nuinerous casts of compressed, broken specimens that occur in a yellowish-colored shaly rock. The cranidium has the general character of that of S. leucosia (pi. 67, figs. 14, 16) and vS". pepinensis (pi. 67, figs, i, 4, 5), but it differs in being proportionately shorter. The frontal limb was gently rounded as in S. leucosia and not flattened as in 5". pepinensis. The free cheeks are rather broad. Thoracic segments of the type of those of Saukia ludcnsis, and the pygidium of the two species is somewhat similar except that of .S. zvardi is longer in proportion to its width. In this respect it has the outline of the pygidium of 6". pepin- ensis, but not the narrow border of the latter. Surface not preserved. The type specimens are in the Peabody Museum, Yale University, New Haven, Connecticut, and plastotypes in the U. S. National Museum, Nos. 58671 and 58672. The species is named after Dr. Freeman Ward of Yale University, and I am indebted to Dr. Charles Schuchert for the opportunity to study and name the species. NO. 13 DIKELOCEPHALUS AND OTHER GENERA 385 Formation and locality.—Upper Cambrian: (346f) Beneath the Natural Bridge limestone ; soft, shaly-yellow rock, probably a decom- posed thin-bedded dolomitic limestone, east side of road about 1.5 miles (2.4 km.) north-northeast of Natural Bridge, south end of Rockbridge County, Virginia (Dr. Freeman Ward of Yale Uni- versity, 191 1 ). Genus OSCEOLIA, new genus This genus is known only by the cranidium, associated free cheeks and pygidium of the type species. These parts occur together in the same layer of sandstone to such an extent that it seems reasonable to consider them as belonging to the species Osceolia osceola (pi. 68, figs. 4-10) . The strong concave frontal limb, broadly conical glabella, and long palpebral lobe serve to distinguish the cranidium from that of Dikclocephalus (pis. 60-63), Sankia (pis. 65, 66) 2iX\77 in synonymy 376 listed with description of genus 375 cf . coloradoensis, fragments from Texas 378 crassimarginata (Whitfield), described and discussed 377 figured, pi. 61, fig. 8 394 pi. 65, figs. 9, 10 402 pi. 66, figs. 2-5, 5a 404 allied to Saukia junia 378 compared with Saukia coloradoensis 2>77 Saukia ladensis Z77 form of dorsal shield compared with Dikelocephalus minne- sotensis 347 formation and locality 378 in association with St. Lawrence fauna 356 in synonymy 277 listed from locality 78b 361 from locality 85 360 with description of genus 375 with St. Lawrence fauna 356 vertical range of, compared with Saukia lodensis 360 cf. crassimarginata (Whitfield), listed from Jordan formation 355 fallax, n. sp., described and discussed 378 figured, pi. 67, figs. 21, 21a, 22, 22a 407 associated with Dikelocephalus in Texas 356 compared with Saukia leucosia 378 Saukia pepinensis 378 Saukia pyrene 378, 382 Saukia marica » 380 NO. 13 DIKELOCEPHALUS AND OTHER GENERA Sattkia—Continued. page fallax—Continued. compared with Saukia nistica 383 Saukia stosei 384 Saukia zvardi 378 formation and locality 378 geoi?raphic distribution 375 listed with description of genus 375 locality of, discussed 361 junia, new species, described and discussed 378 tigured, text-figs. 17 378 allied to Saukia crassimarginata and J^". pcpincnsis 378 formation and locality 379 listed with description of genus 375 ? ? ieptanariim (Wiman), described and discussed 379 compared with Saukia leucosia 379 formation and locality 379 in synonymy 379 listed with description of genus 375 leucosia, n. sp., described and discussed 379 figured, pi. 67, figs. 14-17, 17a 406 compared with new genus Calvinclla 388 CahnucUc spiviger 391 Saukia fallax 378 Saukia f? leptccnarum 379 Saukia pyrene 379, 382 Saukia stosei 379 Saukia wardi 384 formation and locality 379 in association with Saukia pepinensis (Owen) 382 listed from locaHty 78 361 with description of genus 375 with St. Lawrence fauna 356 locality of, discussed 361 lodensis (Whitfield), described and discussed 379 figured, pi. 65, figs. 1-3 402 compared with Conokephalina viisa 388 Saukia crassimarginata 277 Saukia rustica 383 Saukia wardi 384 entire dorsal shields of 347 formation and locality 380 genotype, locality of 360 in synonymy 379 listed from localities 85 and 86 360 with description of genus 375 with St. Lawrence fauna 35^ pustulose surface of 374 stratigraphic range 375 vertical range of, compared with Saukia lodensis 360 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 Saiikia—Continued. page marica ( Walcott) , described and discussed 380 figured, p]. 64, figs. 6, 6a 400 compared with Saukia ^pyrene and 5". fallax 380 formation and locality 381 in synonymy 380 listed from locality 62 ; 361 with description of genus 375 locality of, discussed 361 observations on species 380 pepinensis (Owen), described and discussed 381 figured, pi. 67, figs. 1-13, 13a 406 allied to Saukia junia ; 378 associated with fragments of Dikelocephalus minncsotcusis. 370 compared with Saukia fallax 378 Saukia leucosia 379 Saukia pyrenc 382 Saukia stosei 384 Saukia wardi 384 formation and locality 382 geographic distribution 375 in association with Dikelocephalus cf. liinbatus, Osceolia osceola and Saukia leucosia 382 with Dikelocephalus minnesotensis 381. in synonymy 381 listed from localities 85 and 113 360 from St. Lawrence fauna 356 with description of genus 375 minutely granulose surface of 374 pyrene, n. sp., described and discussed 382 figured, pi. 67, figs. 18-20 407 compared with Saukia fallax 378, 382 Saukia leucosia 379, 382 Saukia marica 380 Saukia pepinensis 382 formation and locality 382 listed from locality 78 361 with description of genus 375 with St. Lawrence fauna 356 locality of, discussed 361 cf . pyrene Walcott, listed from Jordan formation 355 rustica, n. sp., described and figured 383 text-figs. 18-20 383 associated with Eoorthis wichitaensis and Illcenurus sp. undt.. 383 compared with Saukia fallax and 5". lodensis 383 listed with description of genus 375 stosei, n. sp., described and discussed 384 figured, pi. 69, figs. 3-5 410 pi. 70, figs. 12, 12a 412 compared with Saukia leucosia 379 Saukia pepinensis and S. fallax 384 NO, 13 DIKELOCEPHALUS AND OTHER GENERA Saiikia—Continued. page stosci, n. sp.—Continued. formation and locality 384 geographic distribution 375 listed with description of genus 375 occurrence of in Cambro-Ordovician limestones 362 wardi, n. sp., described and discussed 384 figured, pi. 69, figs. 1,2 410 compared with Saiikia faUa.v 378 Saukia Icucosia, S. pepinensis, and 6". lodcnsis 384 formation and locality 385 geographic distribution 375 listed with description of genus 375 occurrence of in Cambro-Ordovician limestones 362 Schizamhon typicalis Walcott, listed from locality 201a 359 Schuchert, Charles, acknowledgments 384 collection by mentioned 346 Scotland Station, Pennsylvania, Lower Ozarkian localities 5911 and 59 o. . 384 sculptilis, see Micromitra. Serpulites murchisoni Hall, listed from locality 113 360 listed with St. Lawrence fauna 356 Shakopee formation, in provisional classification 354 " Shovel-head," common name given to Dikcloccphalus (footnote) 363 shumardi, see Conaspis. " Siliceo-argillaceous dolomite," in St. Lawrence formation 355 sintilis, see Lingulella. Species, previously referred to Dikelocephahis 349 spims'.er, see CalvincUa and Dikelocephahis. spinosa, see Acrotreta. Spirodentalium osceola Walcott, listed from locality 78 361 listed with St. Lawrence fauna 356 Steiiothcca sp. undt., listed from Eau Claire formation 358 Stillwater, Minnesota, Upper Cambrian locality 85b near 371 stoneanus, see Obolits (IVestonia). stosci, see Saukia. Stratigraphic position of the Dikclocephalinae 353 Stratigraphic range of genera of Dikelocephalinae 358 Straparollus ? (Ophilctaf) priinordialis Winchell, listed from Jordan tor- mation 3SS s'iveeti, see Holopea. Synonymic references, species previously referred to Dikelocephahis 349 Syntrophia barabiiensis (A. Winchell), listed from Franconia formation.. 357 listed from Jordan formation 355 listed from locality 78 361 listed with St. Lawrence fauna 356 nundina Walcott, listed from locality 201a 359 primordialis (Whitfield) listed from Franconia formation 357 listed with St. Lawrence fauna 356 primordialis argia Walcott, listed from Franconia formation 357 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 PAGE Teller, Edgar E., acknowledgments to 347 Tellinomya f hambiirgensis Walcott, listed from locality 201a 359 teniiisculpta, see Calvinella. texanus, see Crepicephalus and Dikelocephalus. Texas, Dikelocephalus in 359 Saukia cf. coloradoensis, fragments from 378 Saukia fallax from Upper Cambrian locality 70a 361, 378 Upper Cambrian locality 70a near Burnet 359, 372 thca, see Pagodia. Trempealeau, Minnesota, Upper Cambrian locality 83' 371 Triarthrella auroralis Hall, listed from locality 113 360 listed with St. Lawrence fauna 356 tribtilis, see Dikelocephalus. tumidosus, see Agnostus. typicalis, see Schisambon. Ulrich, E. O., cited in discussion of Calvinella o::arkensis 390 fossils collected by 390 investigation by, during 1013 353 Upper Cambrian, former classification of formations in Wisconsin and Minnesota 353 in provisional classification 354 locality I2g, Arbuckle limestone, Oklahoma 372 locality 20b, Colorado 2)77 locality 62, Adams Hill, Nevada 361 locality 66, Dunderberg mine, Nevada 362 locality 70a, fauna associated with Dikelocephalinse 359 locality 76, New York 2>7^ localities 78 and 78b, Osceola, Wisconsin 361 locality 85, described and fauna listed 360 locality 85b, St. Croix River, Minnesota 371 localities 85 and 86, Wisconsin 370 locality 86 in Wisconsin 360 locality 86b, Lansing, Iowa 371 locality 97, Lake Pepin, Minnesota 371 locality 99, Minneiska (Miniska), Minnesota 379, 388 locality 113, Minnesota 360 locality 151, Gallatin limestone, Montana (footnote) 391 locality 134a, Menomonie, Wisconsin 369 locality 339f , Minnesota 371 locality 346d, Minnesota 2>75 locality 346e, Donald Station, British Columbia. Canada 368 Upper Mississippi Valley, geographic distribution of Dikelocephalus in. . . . 364 revision of Cambrian formations in 353 Van Home, Sir William, specific name given in recognition of 2)7^ vanhornei, see Dikelocephalus. Van Ness quarry, Lodi, Wisconsin, Upper Cambrian localit 86 360, 370 vaticina, see Ozvenella. NO. 13 DIKELOCEPHALUS AND OTHER GENERA PAGE Ward, Freeman, specific name given in honor of 384 specimens collected by 384 wardi, see Saukia. Weller, Stuart, cited from New Jersey report 389 Whitfield, R. P., specimens referred to Dikelocephahis 366 Wilberns formation. Upper Cambrian locality 70a, Texas 359, 372 winona, see Lingulella. Wisconsin, former classification of Upper Cambrian formations in 353 geographic distribution of Dikelocephalus in 364 range of Dikelocephalinse in 359 Upper Cambrian locality 78 at Osceola. 361 locality 78b at Osceola 361 localities 85 and 86 360 wisconsinensis, see Lonchocephahts. Wooster, L. C, collection by, mentioned 346 Worm borings, listed from Eau Claire formation 358