CONTRIBUTIONS TO THE NATURAL HISTORY OF THE COM-MANDER ISLANDS.Leonhard Stejneger and Frederic A. Lucas.(With Plates ii-iv.)A.?CONTRIBUTIONS TO THE HISTORY OF PALLAS' CORMORANT.BYLeonhard Stejneger,Curator of the Department of Reptiles and Batrachians.About forty years ago the Great Auk (Plautus impennis) of the North-ern Atlantic became exterminated. -A vigorous search has been madefor it and its remains; fabulous sums have been paid for skins andeggs; and monographers, among whom some of the most prominentornithologists, have collected together the most minute facts bearingupon its history, and discussed in extreme detail the number of speci-mens extant as well as their individual history, so that the latestaccount of this remarkable bird fills a quarto volume of quite respect,able dimensions. There are now on record about eighty mountedspecimens, or skins, seventy eggs, and countless bones as being pre-served in the various museums of the Old and the New World.Within the same period another large water bird has become extinctin the North Pacific, without having as yet attracted the attention ofthe monographers. It is so rare in collections that only four specimensare known to exist in museums, while nobody is the proud possessor ofits eggs, and no bones had been found or preserved until I was so for-tunate some years ago as to rescue a few of them. Yet, this bird was thelargest and handsomest of its tribe. And so little has been known ofit that there is not yet printed a detailed and good description of it.The bird which has fared so badly is Pallas's Cormorant, or the Spec-tacled Cormorant, Phalacrocorax perspicillatus Pall.I have recorded elsewhere (Proc. U. S. Nat. Mus., vi, 1883, p. 65, andBulletin U. S. Nat. Mus., No. 29, Res. Orn. Expl. Kamtsch., p. 180) myreasons for considering this species extinct and the causes which ledto its extermination. It seems as if the very causes which terminatedthe existence of the Great Auk worked the same result in Pallas's Cor-morant, and it is even probable that if the latter, at some earlier period,Proceedings National Museum, Vol. XII, No. 765. 84 ON PALLAS' CORMORANT STEJNEGER AND LUCAS.also inhabited the other Aleutian Islands, as is most likely, volcaniceruptions may have played a role iu this drama as well as in that ofthe Great Auk. True, the latter was entirely deprived of its power offlight, but it is evident both from the measurements of the skins as wellas of those of the bones, given below, that the wings of this cormorantwere disproportionately small. Steller speaks of its great bulk of bodyand its weight, which varied between twelve and fourteen pounds,* sothat one single bird was sufficient for three starving men of the ship-wrecked crew.With this bulk it combined an unusual " stoliditas," but it is prettyclear that this stupidity, which made them such an easy prey, was duemore to their slowness of locomotion on land and in the air than to anyspecial temperament or dullness of intellect. The natives of BeringIsland inform me that the meat of this species was particularly palata-ble compared with that of its congeners, and that consequently, duringthe long winter, when other fresh meat than that of the cormorantswas unobtainable, it was used as food in preference to any other. Inbrief, all the circumstances combined to make short work at extermin-ating this bird at its last refuge, for there is no evidence that it has everbeen found during historical times in auy other locality than BeringIsland. The result was that Pallas's Cormorant, which was found bySteller and his shipwrecked comrades on that desolate island in 1741,and which at that time?that is, before man ever visited its rockyshores?occurred there in great numbers, "frequenUssimi? as Stellersays, became extinct in about a hundred years from its discovery. Thehistory of this bird forms an interesting parallel to that of the greatnorthern sea-cow (Rytina gigas).Up to 1837 or 1839 Steller seems to have been the only naturalist whohad seen this bird, for, although naming it in his Zoographia, all Pallasknew of the species was derived from Steller's observations, whose description he merely quotes. It is, then, safe to conclude that it was notamong the many water birds collected by Billings's expedition, whichbrought home such rich spoils from the Kuriles and the Aleutian Island,but which did not touch at Bering Island. In the above-mentionedyear Captain Belcher, with the Sulphur, visited Sitka, and was therepresented by Kuprianoff, the Bussiau governor, with one of the speci-mens of this bird in his possession. This specimen is evidently the onenow iu the British Museum, while the others went to the St. PetersburgAcademy, from which one was again secured by the Leyden Museum.Although obtained from the governor in Sitka, there is nothing to indi-cate whence came the specimens; but inasmuch as Bering Island at thattime belonged to the administrative district of Sitka, at which port allthe furs were received from that island before being shipped to Europe, * The average length of wing of adult Ph. perspicillatus is 355mm (see tahle beyon 1)and the weight 12 to 14 pounds. Compare with this the fact recorded by me (Oni.Expl. Kamtsch., p. 186) that Ph. urile, the nearest ally of the present species, weighsonly 5 pounds, with a length of wing of :500mm . V?l889 n'] PROCEEDINGS OF THE NATIONAL MUSEUM. 85all vessels from Bering Island consequently first stopping at Sitka,there is every probability that the specimens in question were collectedon that island. This conclusion is corroborated by the manner in whichP. perspicillatus and Leucosticte griscogenys are mentioned together.So far as known, these are the only specimens iu existence, viz : Twoin the museum of the Imperial Academy of Sciences in St. Petersburg;one in the British Museum, London; one in the "Rijks Museum/' Ley-den, Holland.Several pictures of Pallas's Cormorant have been published. A largecolored plate by Wolf, from the British Museum specimen, is in Elliot'sBirds of North America, a reduced wood engraving copy of which isgiven in the Standard Natural History (or Riverside Natural History),vol. iv, p. 192. The same specimen is also figured in two different posi-tions by Gould in the Zoology of the voyage of the Sulphur, and poorlycopied iu Reichenbach's " Natatorum Novitire." Iu Schlegel's " Dieren-tiuin," p. 281, there is a wood-cut, probably taken from the Leyden speci-men. According to Dr. Fiusch (Abh. Natur. Hist. Ver. Bremen, in,1872, p. 20) this species, undoubtedly from one of the St. Petersburgspecimens, is represented on plate V, Fig. 4, of Brandt's u Icon. Av.Ross," a work which was never published.Dr. Theodor Pleske kindly writes me in regard to the specimens inSt. Petersburg:Through the kind offices of Dr. Pleske I have received from Profes-sor Brandt's heirs that part of the manuscript of his unpublished mono-graph of the Cormorants, which relates to the species, in question, withpermission to publish it. The description is very full, and being the,only accurate and detailed description of the species I take great pleas-ure in printing it in full. In order to avoid any errors I deem it best topublish it in the language in which it was originally written. I havepreceded this description with a* synonymy which is thought to benearly exhaustive. Phalacrocorax perspicillatus Pall.1826.?Phalacrocorax perspicillatus Pallas, Zoogr. Ross. As. II, p. 305.?Gould,Zool. Sulphur, p. 49, pi. xxxii (1844).?Bonaparte, Cousp. Av. n, p. 167(1855).?Id., Coinpt. Rend., 1856, xliii, p.?Taczanowski, Orn. Faun. Vert.Sibir., p. 66 (1877).?Id., Bull. Soc. Zool. France, 1877, p. 41?Ridgway,Noinencl. N. Am. B., p. 51 (1881).?Id., Man. N. Am. B., p. 81 (1887;.?Coues,Check L. and Diet., p. 118 (1882).?Id., Key, 2ed., p.?(18?).?Id., Auk, 1864,p. 144.?Id , Key, 3 ed., p.? (18?).?Stejneger, Pr. U. S. Nat. Mus, vi, 1883,p. 65.?Id., ibid., x, 1887, p. 138.?M, Auk., 1884, p. 173.?Id., Oru. Expl.Kamtsch., pp. 180, 318 (1885).?Id., Stand. Nat. Hist,, IV, p. 191, Fig. 92(1885).?Baird, Brewer, & Ridgway, Water B., N. Am., n., p. 164, tig.(1884).?A. O. U. Code and Check L., p. 351 (1886).1858.?Graculus perspicillatus Lawrence, in Baird, B. N. Am., p. 877 (1858).?Schle-Gel, Mus. P.-Bas, Pelec, p. 17 (1863).? Id., Dierentuio, p. 281, fig. (1871).?Elliot, B. N. Am., pt. ? , pi. 50 ( ).?Gray, Hand-1., in, p. 127(1871).?Coues, Key, 1 ed., p. 304 (1872).?Id., Check L., p. 101 (1873).1850.?Graculus urile Reichenbach, Natat. Novit., pi. xvn, Figs. 2311 and 2312 {neeGmel.) (Cf. Bonap., Consp Av. i, p. 168, and A. B. Meyer, Index Reicheub.,p. 44; no name on the plate !) 86 ON PALLAS' CORMORANT?STEJNEGER AND LUCAS.Brandt's description, here published for the first time, is literally asfollows: DESCRIPTIO.Carbo perspiciUaUis specierum generis Carbonuin bucusque notorum niaximam sis-tere videtur. Corporis euim mole Carborem cormoranum superat.Rostruui robustuin, satis altuni, inodice elongatum, nigrum, apice summo albicauti-corueo, basi marginibusque tamen corueo. Cnlmiuis basis supra rotundata, convexa,medium supra subrectum. Culmiuis margiue anterioris subrecti apex supra dertribasin band proniinens sed angusta sutura distiuctum. Culmiuis superior facies neenon paratonorum atque gnathidiorum apice uncato, acuto, elongato, gonydeni inrostro clauso louge superante. Exterior facies teuuiter per lougitudiuem subelevato-striata, striis teneris plus minusve parallelis. Dertrum in baseos faciei superiorislateribus sulco arcuato satis profundo exaratum, in facie laterali auteui sulcis pa-rum distinctis, transversis, obliquis, subparallelis 2 vel tribus iustructum. Gouyssubrecta et in medio vix proniinens. Myxa apice truncato rotundata.Frontis antica pars, geuae, regio ophthalmica, spatiuui angustum poue oris augu-lnui, mentum et gulae summum initium uuda cinnabariua, albo et coeruleo varia utin gallopavone (Steller). In genis peume brevissimae, solitariae, sparsae. Oculiannulo meinbranaceo, nudo, elevato, subelliptico, lato, albo, perspicilluni quodam-niodo aemulante, cincti. Inter oculi annuluiu et superiorem oris anguli marginemcalvum spatium triangulare pennisbrevibus obsessum.*Alae complicatae vix ad uropygii posterioreni extremitatem porrigeutes.Cauda iuverti subspathulata, basi augustior, e pennis 12 composita.Tarsi pro magnitudine adinodum breves.Color in universum ater. Capitis anterior pars cum gula initio violaceonitens.Capitis posterior pars, collum, pectus, abdomeu, dorsum, crissum et uropygiuui ob-scure vel aureo viride nitentia luce angulo plus minusve recto in observatoris oculosrerlexa plus minusve obscure violascentia. Peunae parapterii et bumerales nee nontectrices alarum supra e subpurpurascnite violaceo-nitidae, anguste nigro-margin-atae, rotundatae vel obtuse subacuminatae, apice fere subellipticae. Remigesprimariae et tectrices alarum inferiores e subfuscescente nigrae. Remiges secunda-riaeuigrae, limbo exteruo plus minusve subnitide purpurascente violaceae. Caudacum tectricibus atra, subopaca. Rectricum scapi supra ad apicem usque albi, mar"ginibus nigricautibus, apice autem cum inferiore facie nigri. Frontis posteriorispartis et verticis penuae dilatatae medio atrae marginibus subpurpureo-violascentevel iuterduiu subvirescente nitidulae in cristam subtetragonam antice angustiorembasi latam, suberectam retrorsum spectantem, postice subtruncatam, 3" fere longamapice 2" latam iusignem elevatae. In occipitis postrema parte et cervicis summocrista alia 2" louga 24" lata, flabelliformis, basi angustior e pennis satis latis atrismargine virescentibus media plus minusve subpurpuresceutibus formata, retrorsumspectans conspicitur. In frontis medio supra oculos, in temporibus et in lateribussuperioris partis colli pennae candidae angustae I ad f lineae latae elongatae, 1-3"lougae, lineares, acutae, fere subsetaceae, subsolitariae sparsae invenieutur, quarumquae iu fronte suut bieviores, interdumpollicares vel paulo ultra; quas vero in colloobservare licet multo longiores, 2-3" lougi evadunt. Praeterea vero etiam in tem-poribus et collo peuuulae albae breves penicilliformes apice tantum radiolatae. Infemoribus macula Candida triangularis a quovis bypochoudrio late incipiens et adcrus usque angulo acumiuatio exteusa e pennis longis, valde acuminatis apicibusradiolis rarioiibus comj>ositis formata. Pedes atri unguibus obscure corneis.Feminae Stellero auctore et cristis et membrana perspicilliformi, alba oculos latecingente carent.Pondus Stellero auctore 12-14 librarum.*Ob bancce aunnlum peculiarem Pallasius baud incommode speciem nostram per-spicillatum nominavit. VOi889. 11 '] PROCEEDINGS OF THE NATIONAL MUSEUM. 87Meusurae avis adultae in Museo Acadeinico servatae.A rostii apice ad caudae apicem 39"ad frontem 3" f}'"ad oris angulum 4" $"'A frouti ad caudae basin 27" 10'"dorsi initium , 14" 7"Ab alarum angnlo humeali ad remigutn apicem 13" '.'>"'Caudae longitude... ....^ ?" 5'"Tarsi lotigittido ^ ; 2" 6'"Longitudo digiti interui ad unguis basin t 1" 3'"secundi 2" V"tertii 3" V"quarti seu externi i;. ., 4" 2"''i have thought it useful to tabulate the measurements given by thevarious describers reduced to millimeters : 88 ON PALLAS' CORMORANT STEJNEGER AND LUCAS.kinds of water birds. Among the latter a particularly large pelvis of aPlialacrocorax at once attracted my attention, and as 1 bad bad Pallas'sCormorant on my mind since I started from Washington 1 was not slowin concluding that I had to do with the bones of this bird. Had I hadtime to dig out the whole deposit I should probably have obtained morebones, but with the above suspicion I did as much digging and collectedas many bird bones as the circumstances would allow.A full account of this find is given by Mr. Lucas in his report whichforms the remaining portion of this article. B.?DESCRIPTION OF SOME BONES OF PALLAS' CORMORANT (PHALACRO-i ( )RAX PERSPICILLA TUS. )BYFrederic A. Lucas,Assistant Curator of the Department of Comparative Anatomy.Dr. Stejneger has very kindly placed in my hands for description thebones above mentioned. They are as follows:Rostral portion of cranium in advance Right fused metacarpals, very iuiper-of the frontonasal hinge, with attached j feet,palatines. Three pelves, lacking pubic bones.Lower mandible.Right ramus of lower mandible.Two nearly complete sterna.Right coracoid.Right humerus.Left humerus of another individual.Right ulna.Right fused metacarpals. Left femur.Two left tibiae.Right tibia.Two left tarsi.Second cervical verlebra.Third cervical vertebra.Ninth (?) cervic.il vertebra.The more important of these are figured on the accompanying plates,all figures being of natural size, and drawn by the author.The bones, although stained, are in a good state of preservation, beingbut slightly weathered, and all are from thoroughly adult iudividuals.For the better aud briefer description of these bones they have beencompared with those of an adult Plialacrocorax carbo, and the oppor-tunity has been taken to test, to some extent, the value of the sub-genera Urile and Phalacrocorax, by comparing at the same time thecorresponding bones of P. urile and P. tlilophus.The former bird is, for the species, large and the latter somewhatundersized, although adult.The rostrum of perspicillatiis is nearly as long as in carbo, but muchmore slender, and is readily distinguished from it by the deep, lateral,longitudinal groove characteristic of the sub-genus Urile.The under surface of the rostrum is less grooved, longitudinally, thanthat of carbo and much less so than that of 7*. urile.The palatines are as long as those of carbo, anteriorly narrower and U. S. NATIONAL MUSEUM PROCEEDINGS, VOL. XII PL. II f ,. L ' ^m ~\. Lateral aspect of rostrum:!. Rijdit ramus <>f lower mandible, external aspect.4. Ri^ht ramus of Lower mandible, internal aspecl5. Right metacarpals U. S. NATIONAL MUSEUM PROCEEDINGS VOL. XII PL. W 1f ? ft ? Q 9 I Bones of Pallas'S Cormorant?natural size. (Page 88.) 1. Left lateral aspect of pelvis. -'. Dorsal aspect of pelvis. U. S. NATIONAL MUSEUM PROCEEDINGS, VOL. XII PL. IV Bones of Pallas's Cormorant?natural size. (Page 88. i1. Right coracoid, ventral aspect.2. Sternum, ventral aspect.3. Femur, anterior aspect. 4. Tarsus, anterior aspect.5. Tibia, anterior aspect. VOi88ftn'] PROCEEDINGS OF THE NATIONAL MUSEUM. 89posteriorly wider, conforming in pattern very nearly to those of urile,while dilophus resembles carbo in this respect.The trans-palatine angle is more rounded than in carbo, much morethan in urile, resembling in this dilophus.The inner portion of the post-palatine is less produced ventrally thanin carbo, and the pterygoid articulation wider and flatter than in carbo,the palatine thus lacking the keel present in carbo.The same differences are found between the same parts of urile anddilophus.The maxillo-jngal bar is as long as that of carbo but more slender.The lower mandible is slightly shorter and decidedly weaker thanthat of carbo, and the lower mandible of urile is proportionately stillweaker than that of dilophus.The dentary portion of the mandible is more deeply grooved alongthe inner surface than that of carbo, being comparatively the same asin urile.The cutting edges of the mandible are comparatively straight as incarbo and dilophus, but urile differs from all three in having the mandi-ble distinctly recurved.The sternum is transversely flatter than that of carbo, being a triflemore flattened even than that of urile. The carina is also shorter thanin urile, but in size and general appearance the sterna of perspicillatusand urile resemble one another very closely.From manubrium to ineso-xiphoid the sternum is 13min shorter thanthat of carbo, being exactly as long as that of urile.The proportion of carina to total length is shorter than iu either carboor urile, the sternum from anterior end of carina to meso-xiphoid measuriug 2,nm less than that of carbo and 4mm less than that of urile.Between the costal borders the sternum is slightly wider than ineither carbo or urile.The rudimentary manubrium, like that of urile, lies in the plane ofthe body of the sternum, while in carbo and dilophus the manubriumlies in the plane of. the keel.If a line be drawn between the costal processes it will be found thatthecoracoid articulatious project less beyond this line and form a moreobtuse angle with one another than they do in carbo, and the same istrue of urile as compared with dilophus. The sternum is non-pneumatic,as in urile, but iu carbo and dilophus good-sized foramina pierce itsdorsal face just back of the ridge formed by the coracoidal groove.It is certainly interesting to find the sterna of these two represent-atives of the sub-genera Phalacrocorax and Urile, respectively, agree-ing with one another in these slight structural poiuts.Articulations are present for five pairs of ribs, the same numberas in carbo. One specimen of urile has four pairs of articulations,another has five on the left side and four on the right, and dilophus hasbut four pairs of costal facets. 90 ON PALLAS' CORMORANT STE.INEGER AND LUCAS.The number of ribs articulating with the sternum is, however, subjectto slight variation, especially among water birds, and without an ex-tensive series of specimens it is a little difficult to be sure of the normalnumber.The coracoid is of the same length as that of carbo, 10mm longer thanin urile ; but, while the proximal end is but little heavier than in carbo,the shaft aud especially the distal end are much more massive.The epicoracoid is prolonged upward into a sharper hook than in anyof the other species at hand, but this process is subject to considerablevariation with age or in various individuals.One humerus is a little longer than that of carbo, the other is of ex-actly the same length; both are much stouter, especially in the proxi-mal half.The humerus is practically non-pneumatic, the foramina being veryminute, while the pneumatic foramina of carbo, though not large, arereadily seen.The humerus of urile differs from that of dilophus precisely as thatof perspicillatus from carbo.The ulna is distinguishable from that of carbo only by its greaterweight, and the same may be said of the humerus of urile as comparedwith that of dilophus.The fused metacarpals are slightly shorter and slightly stouter thanin carbo, and here again the same differences are observable betweenthe metacarpals of urile and dilophus.The "sacrum," as a whole, is as long as that of carbo, but its com-ponent parts are more heavily built.It comprises six presacrals, two true sacrals, and nine post-sacrals,aud the three "sacra" of perspicillatus agree with one another in theseparticulars.Phalacrocorax carbo has six pre-sacrals, two true sacrals, and nineor ten post-sacrals. P. urile has six, two, eight, and dilophus six, two,nine.The hypapophyses of the anterior three vertebras have been brokenoff, but although the compressed centra are larger than in carbo, thehypapophyses seem to have been smaller.The six presacrals present few salient characters, but the dia.pophyses of the fourth vertebras lie at right angles to the vertebralcolumn, while in the three other species the diapophyses of this verte-bra are directed forward.The sacral and immediate post-sacral vertebras vary in the develop-ment of their parapophyses in all four species under consideration.In all three specimens of perspiciUatus the two true sacrals bear noparapophyses, while the two succeeding vertebra* have them extendedto, and ankylosed with, the ilium.The diapophyses and parapophyses of these vertebras are united by athin plate of bone, but that this is due to age is shown by the conditionobtaining in the other species. ^889."'] PROCEEDINGS OF THE NATIONAL MUSEUM. 01These latter also indicate that the canal formed by these processes,the centra of their vertebnc, and the ilium, is larger on the right sidethan on the left, and that it is first obliterated on the left side.In carbo neither the sacrals nor the second post-sacral bear para-pophyses, although these are present on the first post-sacral, uniting itfirmly with the ilium.In one example of urile, slender, but well marked, parapophysesconnect the two sacrals with the ilia.In another and much smaller specimen the second sacral has a para-pohysison the left side, there being no parapophyses on the first sacral.Iu both specimens of urile the first, but not the second, post sacralbears parapophyses. Finally, dilophus has strong parapophyses on thesecoud sacral and first post-sacral, but none on the second post-sacral.The variation in the sacral region of these specimens is not only in-teresting iu itself, but interesting from the fact that it is unusual forparapophyses to be present at all on the true sacral vertebrae of birds.Viewed from above the ridge formed by the confluent spinous proc-esses of the ^sacrals" is wider than in carbo, and the iuterpophysialforamina are nearly closed, while in carbo they are very open.Although these characters depend to some extent on age, they do notentirely, and the same differences exist between the "sacra" of urileand dilophus as between those of perspicillatus and carbo.The pelvis is much more rugose than in carbo, all attachments formuscles being strongly emphasized.The auti-trochanter is placed farther back than in carbo, and is muchmore rounded, thus affording more play to the femur.Just back of the anti-trochanter the outer edge of the ilium is raisedand thickened, forming a flat, subtriangular spot about an inch iulength.This peculiar flattening of the ilia, taken in connection with the sizeand rugosity of the pelvis, is sufficient to distinguish it from that ofother species.The ilium of urile has a flattened spot, but proportionately smallerthan in perspicillatus.Back of this flattened portion the dorsal edge of the ilium is bent out-ward, making this part of the ilium outwardly concave, where iu carboit is convex.The post ilia of carbo and dilophus round gently outward and down-ward throughout their entire leugth from their junction with the dia-pophyses.Viewed from the side the dorsal outline of the "sacrum" is slightlydecurved, while that of carbo is very nearly straight, and the same dif-ference exists between urile and dilophus.The acetabulum is slightly larger and forms more nearly a perfectcircle than in carbo.The ilio ischiatic foramen is subelliptical and wide, the longitudiual 92 ON PALLAS' CORMORANT STEJNEGER AND LUCAS.diameter being nearly twice the vertical, while in carbo this foramen ismore pointed posteriorly, and narrower, the length being more thanthree times the height.In consequence of the size of this foramen the distauce from the dor-sal edge of the ilium to the ventral edge of the ischium is much greaterthan in carbo.The bar of the ischium bounding the obturator space is sharp-edged,rugose, and concave exteriorly on the posterior portion, while the cor-responding portion of the ischium in carbo is comparatively smooth andslightly convex posteriorly.The posterior border of the ischium is straighter than in carbo andthe iliopubic articulation one-third shorter.The femur is 5mm longer than that of carbo, in every way much moremassive, and with all the muscular ridges more pronounced, while curi-ously enough it is more pneumatic, having several foramina in theventral aspect of the neck that are lacking in carbo.There is nothing to distinguish the femur of urile from one of dilo-phus of the same length, and of the two that of dilophus is slightly theheavier.But in the specimen of urile in which the humerus corresponds inlength to that of dilophus, the femur and tibia are both longer andheavier than in dilophus, and the tarsus a little lighter.The phalanges, again, are more massive in urile than in dilophus.The smallest of the three tibise is slightly longer than that of carbo,the cnemial crest is more expanded, and the cuemial ridges farther apartan I more pronounced.The distal extremity of the tibia is also wider than in carbo, but atits smallest diameter the shaft is no larger.The muscular ridges and grooves are more marked than in carbo, butin the absence of more material and making due allowance for individ-ual variation, it is difficult to point out characters which definitely dis-tinguish the tibiae of the two birds.The tarsus is of the same length as in carbo, but much wider, and, asthroughout, with all the ridges more pronounced.Little can be said concerning the three cervical vertebrae, except thatunlike the other bones they are less strongly built than the correspond-ing boues in carbo.From the foregoing notes it will be seen that the differences existingbetween corresponding bones of perspicillatus and carbo also exist be-tween the same bones of urile and dlophus, and that conversely perspi-cillatus and urile agree with one another as do carbo and dilophus.The sub genera Phalacrocorax and Urile, therefore, seem to rest ongood structural foundations, each being characterized by internal aswell as external characters.Unfortunately no skull of perspicillatus is to be had, but the craniaof carbo and dilophus agree with one auother, while differing strikinglyfrom the cranium of urile. XII, "1 PROCEEDINGS OF THE NATIONAL MUSEUM 93From the harmony of the other parts it is not assuming too much tosuppose that the skull of perspieillatus would resemble that of urile.With the exception of the sternum the greater size of the bones dis-tinguishes those of perspieillatus from those of urile, while well-markeddifferences of shape or proportion exist between tlie correspondingbones of perspieillatus and carbo.P. perspieillatus appears to have been a much heavier bird than carbo,and a bird of weaker flight; with more robust and muscular legs, anda more slender and more feeble head and neck.In comparing the following tables of measurements it must be saidthat they do not adequately convey the impression produced by a com-parison of the bones themselves. Thus, in tbe measurements of thelower mandible the greatest vertical width is comparatively as great asin carbo, but from this point the ramus tapers rapidly either way sothat as a whole the mandible is much weaker than that of carbo.So too with the humerus, where the greatest proximal width is only2mm greater than in carbo, although the bone in its entirety is muchmore stoutly built.Measurements (in millimeters) of corresponding bones of Phalacrocorax perspieillatus,carbo, urile, and dilophus.[All measurements are in a direct line and not along curves.] Rostrum : Tipof mandible to extremity of maxillo-jugal barMaxillo-jugal barTip of mandible to posterior end of palatineWidth across nasals, at frontonasal hingeLower mandible : Length of ramusGreatest height of ramusSternum : Anterior end of carina to nieso-xiphoidManubrium to meso-xiphoidDepth of carinaWidth across articulations of first ribWidth across articulations of fourth rib(Joracoid : LengthBreadth of sternal articulationG reatest distal breadthHumerus:LengthGreatest proximal breadthGreatest diameter midway between extremities.Greatest distal breadthUlna:LengthGreatest proximal breadthGreatest diameter of shaft midway between ex-tremitiesPelvis : Greatest length of iliumFrom anterior border of ilium to external angleof anti-trochanter .'.Greatest width of ilia in advance of acetabuia. ..Least width of ilia in advance of acetabuia....Width between outer extren.ities of anti-trochan-tersLength of ilio-isehiatic space P. perspieil-latus (Na-tional 94 ON PALLAS CORMORANT STEJNEGER AND LUCAS.Measurements (in millimeters) of corresponding bones of Phalacroeorax perspicillatutcaroo, urile, and dilophus.[All measurements :ire in direct line and not along curves.] seum, 535).Pelvis?Continued :G.eatest width of ilio-ischiatie spaceFrom dorsal edge of ilium, above the ilio-ischiaticforamen, to ventral edge of ischiumLength of iliopubic articulationBetween posterior terminations of ischiaFemur:LengthGreatest proximal widthGreatest diameter midway between extremities.Greatest distal widthTibia:LengthWidth across cneraial ridgesWidth at distal end of articulation with fibula..Least transverse diameter of shaft..." jDistal width"Tarsns: "LengthProximal transverse widthDistal width P. urile ; P. dilophuK(NationalMuseum,12502). 15+42 (NatiomiMuseum,18050).