1871.] MR. SCLATER ON ATELES VARIEGATUS. 651 



of the female being invariably devoid of such enlargement, it very 

 much interested me to see that in the present species, while the 

 male retained the normal and characteristic structure of this organ, 

 the female enjoyed the same appendage, and that in a degree only 

 slightly less developed. In either sex the trachea is somewhat en- 

 larged above the bulla ossea, and then, as usual, rapidly tapers ; and 

 in both the bulla ossea is outwardly of the same general form as it 

 is in the male of Anas boschas, Linn. I have inquired of Mr. Bart- 

 lett whether any peculiarity was observed in the call-note of the 

 female bird during her captivity in our Gardens, but I cannot learn 

 that such was the case. 



I abstain from making any comments on the curious fact I have 

 mentioned, which is, so far as I am aware, unique; but it would be 

 easy to enter upon some speculations as to its bearings on the im- 

 portant question of "Sexual Selection" which is now being agitated. 

 I will, however, say that, though I know not bow far other ornitho- 

 logists are likely to agree with me, I conceive that, if we wish for a 

 natural subdivision of the two large groups of Anatidce formed by 

 what are generally termed the Anatince and Fuligulince, the charac- 

 ters afforded by the trachea ought to be fully studied ; and I venture 

 to refer to some suggestions on that question which I published some 

 years ago in America*. It should be one of the first objects of 

 every collector in foreign countries to examine the trachea of each 

 bird that he skins ; and nowhere is this more necessary than with 

 members of the Anatidce. 



I am much averse to inventing new groups ; but I think it very 

 possible that this species, being thus shown to differ so singularly 

 from any Duck with which we are acquainted, will be made the type 

 of a new genus or subgenus ; and as *ome enthusiast may wish when 

 conferring a name on a section so established to celebrate that of 

 some notable person of the gentler sex who is gifted with masculine 

 attributes, I think it as well to anticipate such a proceeding, and 

 therefore suggest that if a new division be found expedient it should 

 bear the appellation of Virago^, as a tribute to the virile character- 

 istic of the ladies in question and of the female of this species of 

 Duck. 



November 21, 1871. 



Professor Flower, F.R.S., V.P., in the Chair. 



Mr. Sclater exhibited and made remarks on a fine skin of Ateles 

 variegatus, Wagner ( = A. bartletti, Gray), which had recently been 

 received by Madame Verdey of Paris in a collection from Oyapok, 

 situated on the river of the same name on the eastern limits of 



* Eeport of the Smithsonian Institution for 18(50, p. 420. 



t Virago e genere Anatino cujus foemina eaderu qua?, mas organa vocis habet 



