NEW FRESH-WATEE GASTROPOD MOLLUSKS OF THEGENUS CHILINA OF SOUTH AMERICA
By William B. MarshallAssistant Curator, Division of Mollnsks, United States 'National Museum
The five new species herein described have recently been addedto the collection of the United States National Museum, or havebeen in the collection unnamed or wrongly identified.Genus CHILINA GrayCHILINA BULLOCKI, new speciesPlate 1, Figures 4, 6Shell rather thin, ovate. Whorls moderately rounded, but muchlonger than wide, i^xial sculpture of very obscure incrementalstriae, slightly crenulating the suture. Spiral sculpture of faintindications of revolving striae. Color of type dark olive-green witha band of interrupted reddish spots a short distance below thesuture and three nearly continuous bands of the same color lowerdown on the whorl. Externally these bands are faint, but in theaperture they show plainly although thinly coated with the whiteand pinkish of the interior. Aperture about two-thirds the lengthof the shell, outer lip simple, columellar lip white, its lower partnearly straight, broad, reflected over a false umbilicus on the leftmargin, and with an oblique strong, entering fold at its upper end.Parietal wall with a thin white callus and a revolving plait on itslower portion. Interior whitish, flushed with pink, the reddishbands of the exterior showing plainly.Type.?TlciQ type (U.S.N.M. No. 414163) measures: Length, 27mm; diameter, 15 mm; length of aperture, 19 mm; axial length ofbody whorl, 23 mm. It and 24 paratypes (U.S.N.M. Nos. 414164,414165) were collected and presented by D. S. Bullock, of the Es-cuela Agricola de " El Vergel," at Angol, Chile, and came from the
" mill canal that comes from Rio Malleco, El Vergel, Angol, Chile,November, 1928." Four other paratypes were returned to Mr.Bullock.No. 2949.?Proceedings U. S. National Museum, Vol. 82, Art. 8150259?33 ^
2 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 82Remarks.?As shown by the figures, this species is related to C.iheHngl Marshall, but is much smaller, and more ovate. Like othersfrom this general region, this species shows a tendency to have thewhorls shouldered, the body whorl inflated, and the length of theshell in proportion to diameter to become less. It is related also toC. iulloides Orbigny.Plate 1, Figure 6, shows the color marking revealed by removal ofthe periostracum of a paratype (U.S.N.M. No. 414164).CHILINA IHERINGI. new speciesPlate 1, Fioitie 8Shell large, inflated, ovoid. Spire short, apex lost. Body whorlvery large, about seven-tenths of the length of the shell, subcylindri-cal, its outer wall nearly vertical, slightly shouldered. Axial sculp-ture consisting of fine incremental threads, the longer rest periodsemphasized by greater strength and deeper color. Spiral sculptureof irregularly spaced impressed lines and crude riblets, which becomemore prominent on the basal area. Surface slightly malleated.Suture crenulated. Color light olive-yellowish with four revolvingbands of reddish, the upper one well marked, the others hardlyvisible except when viewed through the shell by transmitted light.Aperture very long, its outer wall slightly compressed, outer lipthin. Interior whitish, the external bands showing through, espe-cially if held up to the light. Columella straight, stout, broad,white, with a strong entering fold at its upper part. A false um-bilicus formed by the reflecting of the left margin of the columella.Parietal wall with a thin callus.Type.?The type (U.S.N.M. No. 414166) measures : Length, 45 mm
;
diameter, 27 mm ; length of aperture, 30 mm. It and two paratypes(U.S.N.M. No. 363765) come from Lake Todas Santos, Province ofLlanquihue, Chile, received from Dr. H. von Ihering. This lake ison the Pacific side of the Andes and drains into the Gulf of Cor-covado. A fourth specimen (U.S.N.M. No. 362988) was receivedfrom Dr. F. Felippone, with the general locality, Chile. It is almostan exact counterpart of one of the paratypes and probably camefrom the same locality.R&tnarks.?Until lately the author regarded this as an optimumcondition of the inflated form of C. oldroijdae Marshall. The greatsize of C. iheringi and the different locality indicate that they belongto two species or to two subspecies of the same original stock.
ART. 8 SOUTH AMERICAN GASTROPODS MARSHALL 6CHILINA LLANQUIHUENSIS, new speciesPlate 1, Figure 1Shell globose-ovoid, polished. Whorls well rounded; sutures notdeep, but margined by a stout revolving thread. Axial sculptureweak, consisting of faint threads of growth, the rest periods moremarked in strength and darker color. Spiral sculpture lacking.Color dark olive-green marked with five bands of spots of chestnut,scarcely visible outside, but very prominent within. Body whorlslightly inflated, outer lip thin. Columella slightly broadened, erect,its upper extremity with a sharp oblique entering fold. Parietalwall rather thickly coated with callus and bearing a small spiral foldat its middle portion, its upper portion stained with bright chestnut.Interior white, the color bands very prominent.Type.?The type (U.S.N.M. No. 414167) measures : Length, 16 mm;diameter, 13 mm. It and a paratype (U.S.N.M. No. 363766) werepresented by Dr. H. von Ihering and came from Lake Llanquihue,Chile. This lake drains directly into the Pacific Ocean, and has alsoa connection by canal with the Gulf of Chaco, the northern end of theGulf of Corcovado.Remarks.?This species shows no very close relationship to anyother. It may be distantly related to its geographically nearestneighbor, 0. hulloides Orbigny, of the island of Chiloe, Chile. Ahighly polished periostracum such as possessed by this species, whilenot unknown in other species, is of rare occurrence.CHILINA SIMPLEX, new speciesPixATE 1, Figures 2, 9Sholl rather thin, slender, elongate-ovoid. Spire very short,about 1 mm in length; the body whorl very long, about 13 mm;suture well marked, but not shouldered. Axial sculpture consistingof many fine threadlike striae, invisible to the unaided eye butrevealed by a lens. Rest periods easily seen, partly because stouterthan the growi;h striae, but more because they are emphasized bydarker color. No indication of spiral striae. Color almost uniformlight olive-green, with two scarcely visible bands of pale reddisharrowhead spots, which are more easily seen within the apertureor by transmitted light. One of these bands is a short distance be-low the suture, the other two-thirds down the whorl. There arealso a few faint spots of the same color, indicating the possibilityof more bands possible to the species. Aperture long, rather nar-row. Outer lip simple, columellar lip w^iite, rather broad a?d
4 PBOCEEDINGS OF THE NATIONAL. MUSEUM vol.82nearly flat and reflected to form a slight appearance of an umbilicus.The fold on the columella, characteristic of the genus, is very small,situated rather high up and within, so that it does not show in afront view. Parietal wall with a thin, transparent callus.Type.?The type (U.S.N.M. No. 414169) measures: Length,14.5 mm ; diameter, 7.5 mm ; length of aperture, 10 mm. It and ayounger specimen (U.S.N.M, No. 363022) were presented by Mrs.T. S. Oldroyd and were collected by J. W. Pemberton, December26, 1914, in the Santa Cruz River at the outlet of Lake Argentino,Province of Santa Cruz, Argentina. The latitude and longitudequoted on the label are 50? 15' S. and 71? 48' W., respectively.Remarks.?This interesting species makes a near approach to be-ing unicolored and upon cursory examination it would be said tobe uniform light olive-green, but closer scrutiny shows it to possessthe reddish spots and tinges characteristic of the genus. What spotsshow are arranged in bands and have a marked tendency to assumean arrowhead pattern. The sculpture, though nearly microscopic,is essentially the same as that of C. I'hnnaeformis Dall, type ofDall's subgenus Pseudochilina (U.S.N.M. No. 56423), and werethat subgenus valid the species might be placed with it. In theweak, nearly lacking columellar fold it would fall into the sub-genus Acyrogonia Mabille, in which the columellar plait is saidto be lacking, but that subgenus is founded upon a character whichshows every degree of variation in strength as we turn from speciesto species. I have never seen a specimen of Ghilina in which thecolumellar fold was entirely lacking. It may be very weak and nearlyhidden by being set high up on the columella and nearly on itsinner edge, but careful examination always has shown that it ispresent and fulfills in all particulars the definition of typical OhUina.The new species here described is a case exactly to the point. G.simplex is related to a number of other species, perhaps the nearestbeing C. fulgurata oligoptyx Pilsbry. Both are probably descendedfrom the same or nearly related ancestors. It is related also to G.parchappi minor Marshall of Mar del Plata, Argentina, So faras known to the author, all the species of Ghilina which have a veryweak fold belong in the Atlantic drainage. The one described byMabille {G. fusca) and the one by Mabille and Rochebrune {G.nervosa) came from Punta Arenas, Argentina, which is near the half-way point of Magellan Strait and hence can be said to be in neitherthe Atlantic nor the Pacific drainage, but in both.
ABT. 8 SOUTH AMERICAN GASTROPODS?MARSHALL OCHILINA NEUQUENENSIS, new speciesPlate 1, Figure 5Shell rather thin, slender, very elongate, turreted. Spire one-halfthe length of the whole shell, sharply acuminate. Whorls about6.5 (nuclear whorl lost). Early portion of shell normal but amarked ridge begins to develop upon the upper portion of the whorl,which on the later whorls becomes almost a carina, forming a slop-ing shoulder. Suture well marked, slightly crenulate. Axial sculp-ture consisting of numerous, irregular growth riblets, with longerrest periods more strongly marked. Spiral sculpture of two impressedlines near the suture, several revolving riblets on the lower partand faint indications of spiral striae. The crossings of the spiralriblets by the axial sculpture give a malleated appearance to thelower portion of the body whorl. Ground color olive-yellowish withzigzag flashings of reddish on the upper whorls, two bands of arrow-head markings of the same color, and three like-colored plain bandson the body whorl. Aperture very long and narrow, its outer wallperpendicular, outer lip broken off but evidentlj^^ simple. Columellaarcuate, rather broad, white, with a prominent entering oblique foldnear its middle portion. Parietal wall with a thin, white callus.Color of interior pinkish overlaid with a thin deposit of white, theexterior banding and arrow markings showing through.Type.?T\\Q type (U.S.N.M. No. 414168) measures: Length, 37mm; diameter, 18 mm; length of aperture, about 18 mm. It wascollected in December, 1926, in " Las Lagunas," Province of Neuquen,Argentina, by Senor JVIendez, of Santiago, Chile, and was presentedby D. S. Bullock, of Angol, Chile. As the Province of Neuquen ison the east side of the Andes, this would be in the Atlantic drainage.When received, the specimen was completely encrusted, except theaperture, with a thick deposit of iron, through which no hint of thecolors could be seen and which to a large degree concealed the formof the shell. Oxalic acid quickly removed the iron, revealing a goodspecimen except for the lost nucleus and broken outer lip.Remarks.?The nearest relative is CMlhia oldroydae Marshall,which occurs in Lake Fetalafquen, Province of Chubut, not very farsouth of Neuquen. C. oldroydae is a much larger, more inflatedshell than C. 7i?uquenemw. The former, as shown in figures withthe original description, varies from bulimoid form to a turretedform on one side and to a nearly globose form on the other side.The two species may have had a common ancestry, or G. neuquenen-sis may be a subspecies of C. oldroydae or an extreme developmentof the turreted form of the latter. In slenderness, O. nevquenensisvies with C. ficeglensw E. A. Smith for first place, but in otherrespects the two species are not closely related.
b PROCEEDINGS OF THE NATIONAL MUSEUM vol. 82, art. 8CHILINA LIMNAEFORMIS DallPlate 1, Figures 3, 71870. Chilina (Pseudochilina) limnaeformis Dall, Ann. Lye. Nat. Hist. (NewYork), vol. 9, p. 357.1881. Chilina (Pseudochilina) limnaeformis E. A. Smith, Proc. Zool. See. Lon-don, p. 846.1911. Chilina linmaeformis Dall, in Pilsbry, Non-marine Mollusca of Patagonia,Reports of Princeton University Expedition to Patagonia, 1896-1899, vol. 3,p. 531.This species is the type of the subgenus Pseudochilina Dall, de-scribed at the same time. The subgenus was defined thus : " shellthin, covered with a rough fibrous epidermis; spire elevated, acute."Under the description of the species, he says : " The curious epi-dermis and broad plicate columella alone distinguished this singularshell from a Limnaear As this type (U.S.N.M. No. 56423) hasnever been figured, a view of it is given in this paper.By " fibrous epidermis " Dall probably meant that the axial sculp-ture consists of numerous threadlike incremental lines. In dis-cussing this type specimen Pilsbry said : " The irregular or fibroussurface which served to characterize the subgenus, seems to me tobe wholly due to erosion, the cuticle or periostracum being lost fromthe unique type in the National Museum. In other characters theshell is a typical ChilinaPThe shell was more or less covered with a deposit of lime and dirtas often occurs with shells, especially those from lacustrine habitats.When this deposit is removed, the periostracum is revealed as presenton all but a portion of the front aspect and is normal. The " fibrous "appearance is due to the axial incremental threads underlying theperiostracum. Pilsbry is right in thinking the species is not sub-generically different from the genus. The locality quoted, Chile, isindefinite. The shell probably classifies with others having a ratherthin shell, and a broad columella with a prominent, nearly horizontal,fold such as C. oldroydae Marshall, and C. iheringi Marshall of thepresent paper. It may eventually prove to be a young specimen ofsome already described species.
U. S. GOVERNMENT PRINTING OFFICE: t9S?
U. S. NATIONAL MUSEUM PROCEEDINGS. VOL 82, ART. 8 PL. 1
GASTROPODS OF THE GENUS CHILINA
1 . Chiliiia Uanquihuensis, new species; 2, C. simplex, new species (natural size); 3, C. ( Pseiidochilina)lymnaeformis Dall (type, natural size); 4, C. bullocki, new species; 5, C. neuguenensis, new species;fi, C. bullocki, paratype showing coloring revealed by removal of the periostracum; 7, C. (P.)lymnaeformis Dall (type, X 3); 8, C. iherinyi, new species; 9, C. simplex, new species (X 3).
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