88 SHVFEL.vr, Osteology of Harris's CornioyaHl. [isf'"oct 



unusually large " occipital style," and with great rigidity of the 

 cranio-facial hinge. I have no explanation at hand for this 

 discrepancy. It has almost the appearance of having belonged 

 to some other species ; and had I at hand nothing beyond the four 

 above-mentioned skulls to represent N amiopterum harrisi — that is, 

 the ones numbered 19,719, 19,720, and these being in such close 

 agreement in ail particulars — this one (No. 19,628), being so much 

 smaller, and exhibiting, as it does, some other slight differences, I 

 certainly would have been justified in taking it to be the skull of 

 some other species of Nannoptermn. 



Other species of Cormorants, however, exhibit the same differ- 

 ences in size, where the skulls all appear to have belonged to fully 

 adult individuals ; for example, in the case of P. penicillatus, one 

 skull at hand (No. 940, Coll. U.S. Nat. Mus.) has a length of 

 143 millimeters, while another (No. 18,535, Coll. U.S. Nat. Mus.) 

 measures but 126 mm. in length, and with all other measure- 

 ments and diameters proportionately less. The same thing is 

 also found to obtain in P. urile, one skull at hand having a length 

 of 117 mm., and another, from an adult, but 113 mm. — the first 

 being No. 12,502 and the latter No. 12,505 of the collections of 

 the U.S. National Museum. 



Up to the present time, classifiers of the Cormorants seem 

 to have held — and still hold — very diverse opinions as to the 

 generic and sub-generic divisions of the family. Ridgway retained 

 in the genus Phalacrocorax all the known species of North America, 

 and if he considered the genus composed of two or more sub- 

 genera, he has not designated them by name in his " Manual." 

 Coues, on the other hand, recognized no fewer than six sub-genera 

 for the genus Phalacrocorax. taking into consideration the North 

 American forms alone (" Key," 5th ed.) Of the world's Cor- 

 morants, Sharpe, in his " Hand-list," places 41 species of these 

 birds in the genus Phalacrocorax without any' sub-generic dis- 

 tinctions, including among them Phalacrocorax perspicillatns, 

 which he claims to be " extinct " ; then, with this form, and this 

 foiTn alone, creates for it the genus Pallasicarbo, giving us Pallasi- 

 carbo perspiciUatus ! Here, then, the same species is placed in 

 two different genera in the same work. We also have here 

 Nannopteritm harrisi and the fossil genus Actiornis with one 

 species — A. anglicus. There are also some ten fossil species in 

 Phalacrocorax in the " Hand-list." 



Turning next to the A.O.U. " Check-list " for 1910, we have 

 Phalacrocorax divided into three sub-genera — viz., Phalacrocorax, 

 Compsohalieus, and Urile, while Pallas's Cormorant {Phalacro- 

 corax perspiciUatus) occurs nowhere in the volume, not even in the 

 index, among birds living or extinct. 



These facts are ?et forth here with the view of economy in the 

 matter of making comparisons of the skull of Nannoptermn with 

 other Cormorants, for the skulls of the species belonging to the 

 Phalacrocorax series of the A.O.U. " Check-hst " differ very 

 markedly from those of the Urile series, holding apparently a 



