oberholser: new genus of anatidae 571 



ORNITHOLOGY. — Diagnosis of a neiv genus of Anatidae from 

 South America. Harry C. Oberholser, Bureau of Bio- 

 logical Survey. 



The genus Alopochen Stejneger, as at present constituted, con- 

 tains two recent and three fossil species. The former are Alo- 

 pochen aegyptiaca, from Africa, and Alopochen. jubata, from South 

 America. Such widely separated ranges naturally raise a ques- 

 tion regarding the generic identity of these two living species, 

 which doubt has already found expression in the statement of 

 the most recent authority on the family Anatidae.^ Examina- 

 tion now shows that these two species are really generically dif- 

 ferent; and since Anas aegyptiaca Linnaeus is the type of Alo- 

 pochen, a new generic name is necessary ior Anser jiihatiis ^^\x. 



Neochen,^ gen. nov. 



Chars, gen. — Similar and nearest to Alopochen Stejneger, but bill 

 smaller, relatively shorter, and more conical, little more than one-half 

 the length of head (instead of nearly as long), its height at base more 

 than one-half the length of the exposed culmen (instead of much less) ; 

 exposed culmen about one-half the length of the tarsus (instead of much 

 more) ; vertical outline of culmen more concave ; angle of feathers on 

 the base of the culmen sharper and more prominent (less rounded), 

 the reentrant angle of the bare area on each side of the culmen deeper 

 and more pronounced; tertials and scapulars very much narrower and 

 more pointed; nostrils apparently more elongated. 



Type. — Anser jubatus Spix. 



Remarks. — Concerning the proper applicability of the name Alo- 

 pochen Stejneger, a few remarks may not be out of place in this connec- 

 tion. This generic term was originally proposed by Dr. L. Stejneger^ 

 in the text of a popular account. The name there appears simply in 

 the combinations Alopochen aegyptiaca and Alopochen juhata, without 

 mention of a type species or of any reason for the change. The type of 

 Alopochen must, therefore, be determined by subsequent designation. 

 Count Salvadori, in the work to which reference has already been made,^ 

 quotes Alopochen as equivalent to Chenalopex Stephens,^ but gives no 



1 Salvador!, Cat. Birds Brit. Mus. 27: 166. 1895. 



'^ Neos, novus;Xi7»', anser. 



3 Stand. Nat. Hist. 4: 14C-141. 1885. 



* Cat. Birds Brit. Mus. 27: 166. 1895. 



^ Gen. Zool. 12^: 41; 1824. (Type by monotypy, Anas aegyptiaca Linnae). 



