112 SnvFKhDT, Osteology of Harris's Cormorant. [is.t^'o'ct. 



Conclusions. 



Osteologically, N annopterum harrisi presents all the characters, 

 with the usual specific variations, found in the Phalacrocoracidce 

 generally. Its title to generic distinction rests entirely, in so far 

 as its skeleton is concerned, upon those morphological changes 

 which have taken place in its osseous and other systems, due to 

 the gradual loss of the power of flight. In other respects it is a 

 true Cormorant, and had it never become flightless, and the 

 result not taken place in its structure, there would have been no 

 occasion to remove it from the genus Phalacrocorax. 



In that genus it sees its nearest relatives among the " long- 

 faced," more or less compressed crania types, though not the 

 extremes among them, as, for example, the Urile series. With 

 respect to its skull as a whole, it agrees best with some individuals 

 of P. penicillatus ; while, upon the whole, in the remainder of its 

 osteology, it is as near allied to Phalacrocorax perspicillatus — the 

 extinct PaUas's Cormorant — as it is to any other form now existing 

 in the world's avifauna. 



Explanation of Plates. 



(All the figures in the Plates, with the exceplion of Plates XVll. and 

 XVIII. (where they are reduced about one-fourth), are ol 

 natural size,* being reproductions of photographs made direct 

 from the specimens by the author.) 



Plate XV. 

 Fig. 1. — Skull of adult N annopterum harrisi. Direct superior view. 



Large occipital style in normal position. (No. 19.628, Coll. 



U.S. Nat. Mus.) 

 Fig. 2. — Lower mandible of A', harrisi. Direct superior view. 



Belongs to the skull shown in fig. 1 above. 

 Fig. ^ — Skull of Brandt's Cormorant {Phalacrocorax penicillatus), 



adult. Viewed directly from above. Mandible, quadrates, 



and occipital style removed. (No. 940, Coll. U.S. Nat. Mus.) 



The removal of the quadrates allow the zygomas to spring 



inward too near the mesial plane of the cranium. 

 Fig. 4. — Skull of adult N. harrisi. Direct left lateral view, with 



mandible detached and occipital style in position. (No. 



19,720, Coll. U.S Nat. Mus.) 

 Fig. 5. — Skull of Harris's Cormorant (A^. Artrn'si;. Adult. Viewed from 



above. Mandible and occipital style removed. (No. 19,720, 



Coll. U.S. Nat. Mus.) 

 Fig. 6. — Skull of an adult Red-faced Cormorant (P. urile). Viewed 



directly from above, with lower mandible removed. (No. 



12,505, Coll. U.S. Nat. Mus.) 



Plate XVI. 



Fig. 7. — Dorsal view of the sternum ol N. harrisi. (No. 19,720, Coll. 

 U.S. Nat. Mus.) Skull belonging to this skeleton is shown 

 in fig. 5, Plate XV., above: 



* Dr. Shiifeldt's pl.-ites were reduced by about one-tliird to fit the page. 



