AHT. 5. 



FOSSIL BIRDS FROM ARIZONA WETMORE. 



in form and in size with that of the eared grebe. It is distinctly 

 larger than that of C. dominicus and is smaller and less robust than 

 the coracoid of G. auritus. 



Family ANATIDAE. 



QUERQUEDULA, species. 



This genus of teals is recorded on the basis of the distal portion 

 of a left metacarpal, a badly broken right metacarpal in two parts, 

 and two fragmentary ulnas exhumed two miles south of Benson. 

 The fragments in question agree rather closely in contour with 

 Quer que fluid discors^ but are slightly larger and vary 

 in minute details of outline. Until a larger series of 

 Q. discors and Q. cyanoptera is available to demonstrate 

 individual variation in this genus I do not care to assign 

 these specimens a specific name. It is highly probable 

 that they come from a species now extinct. 



DENDROCYGNA EVERSA, new species. 



Characters. — Proximal part of humerus similar to 

 that of Dendrocygna hicolor (Vieillot) but smaller; 

 shaft more sharply ridged at upper end on posterior 

 surface; deltoid ridge extending parallel to line of 

 shaft, reaching to base of tuberculum externum: 

 crista inferior forming an acute angle with side of 

 shaft; caput humeri relatively thicker, with more pro- 

 nounced overhang on posterior surface. 



Description. — Tyi^Q, Cat. No. 10547, U.S.N.M., 

 proximal half of right humerus (figs. 1 and 2), col- 

 lected by J. W. Gidley, April, 1921, in quarry on Sec. 

 22, T. 17 S., E. 20 E., two miles south of Benson, 

 Arizona. Upper Pliocene. 



Shaft slender, slightly elliptical below nutrient foramen, becoming 

 strongly triangular at level of crista superior, and continuing thus 

 to head; nutrient foramen located on lower side; shaft becoming 

 sharply ridged at level of lower edge of crista inferior, and continu- 

 ing thus to base of humeral head, where the ridge merges into a 

 rounded surface ; deltoid ridge beginning at margin below lower end 

 of crista superior, and passing in a slight curve obliquely forward, 

 interrupted for the space of 5 millimeters in center, and then con- 

 tinued as a well-marked ridge that broadens to disappear at lower 

 margin of articular surface of tuberculum externum ; tuberculum ex- 

 ternum elevated, with articular surface extensive, triangular in form, 

 excavated slightly, delimited externally by a sharp angle, and pro- 

 jecting proximally beyond lower margin of caput humeri; caput 

 humeri relatively small, contracted toward external tubercle, ex- 



FlG. 1, — Prox- 

 I M A L POR- 

 TION OF HU- 

 HERDS 



(Type) of 

 Dendrocyg- 

 na EVERSA, 

 POSTERIOR 



AaEW. (Nat. 



SIZE.) 



