1894.] NATURAL SCIENCES OF PHILADELPHIA, 115 



A REVISION OF THE GENUS ANOUS. 

 BY WITHER STONE. 



Having recently had occasion to identify some specimens of Anous 

 and make comparison with Gould's types of A. leucocapilliis and A. 

 melanops, I was surprised to find what confusion existed in regard to 

 the proper disposition of the names which have been proposed for 

 several members of the genus. 



With the object of straightening out the synonymy of the group I 

 have made a careful study of the literature bearing upon the subject 

 and have examined the large series of specimens in the museum of 

 the Academy of Natural Sciences of Philadelphia, and a number of 

 specimens loaned to me by the U. S. National Museum through the 

 kindness of Mr. Robert Ridgway. 



The species of the genus Anous are separable into two groups, the 

 larger dark colored birds (Anous) and the smaller light colored ones 

 {Pwcelsterna). 



Of the latter there seem to be two well marked species, A. caeru- 

 leus and A. cinereus, though Mr. Saunders, strange to say, unites 

 them in his monograph of the Sterniuae (Proc. Zool. Soc. 1876, p. 

 671) ^^'^thout comment. 



In regard to the dark colored species there has been no confusion 

 in connection with the two large species, A. stolidus and A. galapa- 

 gensis, but when we study the smaller species we immediately find 

 difficulties. 



Four names have been employed for the three recognizable species: 



Sterna tenidrostris Temm. PI. Col. 202 (1838). 



Anous melanops Gould. P. Z. S., XIII, p. 103 (1845). 



Anous leucocapmus Gould. P. Z. S., XIII, p. 103 (1845). 



Anous melanogemjs Gray. Gen, Birds, III, p. 661, PI. 182 

 (1849). 



Gould's A. melanops is regax-ded by Mr. Saunders as a synonym 

 of J., tenidrostris (Temm.) and a comparison of the types with Tem- 

 minck's plate amply confirms his decision. 



The ^1. leucocdpillus of Gould, however, is the bird which Mr. 

 Saunders figures and identifies as A. melanogenys Gray. What 

 Gray's bird really is I am unable to say; if it is the species with 



