NO. 20 PLIOCENE Bllil) REMAINS^ — WETMORE 3 



The assemblage of birds is wholly of species of aquatic habit, thus 

 bearing out Gidley's belief that the deposits were formed in bogs or 

 swampy areas. 



A detailed discussion of the birds identified follows. Drawings 

 illustrating this report have been made by Sydney Prentice. 



ANNOTATED LIST 



Order COLYMBIFORMES 



Family COLYMBIDAE. Grebes 



COLYMBUS sp. 



The distal end of a left humerus (U.S.N.M. no. 12825) was found 

 by Elmer Cook in October 1930 at a site 6 miles south of the main 

 quarry and about 300 feet above the level of the river. The specimen 

 is identical in form with living Colymhus nigricollis and C. auritus, 

 these two being identical in conformation and also indistinguishable in 

 size in the part concerned. 



Colymbidae 



The head of a femur (U.S.N.M. no. 12242) from the deposit 

 3 miles south of the Plesippus quarry and 200 feet above Snake River 

 comes from a grebe, intermediate in size between the horned and the 

 Holboell's grebe, that differs in its details from any of the genera of 

 the family Colymbidae found in North America today. It seems to 

 represent a distinct genus and certainly an unknown species but is 

 considered too fragmentary to name at present. 



Order PELECANIFORMES 



Family PELECANIDAE. Pelicans 



PELECANTJS HALIEUS sp. nov. 



Characters.— Rsidius (figs. 1,2) similar in form to that of modern 

 Pelecanus erythrorhynchos Gmelin ' but much smaller ; slightly smaller 

 than mod&vn Pelecamis occidentalis occidcntalis Linnaeus,' with bicipi- 

 tal tubercle located nearer to head. 



Xypc U S N.M. no. 12233, proximal portion of right radius, col- 

 lected July 20, 1931, by Norman H. Boss, from Upper Pliocene 



'Pelecanus erythrorhynchos Gmelin, Syst. Nat., vol. i, pt. 2, 1789, P- 57i. 

 ■Pelecanus Onocrotalus ^ occidentalis Linnaeus, Syst. Nat., ed. 12, vol. i, 



1766, p. 215. 



