306 



NEW YORK STATE MUSEUM 



perspicillata. Possibly in some Anatinae, too, the distal joint 

 of index digit may not bear a claw, though I am inclined to think 

 that nearly ail ducks show this character. Clangula may oc- 

 casionally prove to be an exception in this particular, as I have seen 

 specimens where it was undoubtedly absent. Age possibly had 

 something to do with this, though in nestlings of birds of certain 

 other groups possessing this claw, it is well developed, as we see 

 it among certain gallinules. 



OSTEOLOGY OF THE ANSERINAE 



The geese constitute a pretty well defined subfamily in America 

 including as I have already said above, representatives of the genera 

 Chen, Anser, Branta, Philacte, and Dendrocygna. The birds in- 

 cluded in the latter genus are very peculiar, and exhibit many in- 

 teresting osteological characters. At the present writing I have 

 only an incomplete skeleton of Dendrocygna autumnalis, 

 and this will be described further on. These " tree ducks " have 

 by some authorities been retained among the Anserinae, endowed 

 only with generic rank. This was the view of the compilers of 

 the American Ornithologists' Union Check-List of North American 

 Birds [Ed. i]. 



Of other material I have skeletons of Branta canadensis ; 

 B. c. hutchinsii; B. nigricans; Anser a 1 b i - 

 f rons ; Chen h . nivalis; and odds and ends of others. 

 Unfortunately I have no skeletons of the so called " shel- 

 drakes " of the genus Tadorna, as T . corntita and T . v u 1 - 

 panser, for it is very likely that through such forms as these 

 the Anatinae osteologically gradually shade into the geese, and 

 somewhat less evidently ink) the swans. For example Newton has 

 said, " The genus Tadorna, as shewn by its tracheal characters, 

 seems to be most nearly related to Chenalopex, containing the bird 

 so well known as the Egyptian goose, C. aegyptiaca, and an 

 allied species, C. jubata, from South America. For the same 

 reason the genus Plectropterus, composed of the Spur-winged geese 

 of Africa, and perhaps the Australian Anserinas and the Indian 

 and Ethiopian Sarcidiornis, also appear to belong to the same group, 

 which should be reckoned rather with the anatine than with the 

 anserine section of the Anatidae." 1 



Newton has further said in the Dictionary of Birds [pt 2], that 

 representatives of "the genera Chenalopex (the Egyptian and Orinoco 



1 Sheld-drake, Encyclo. Brit. 1886. v. 21. 



