no 



Dr. K. W. Shufeldt on the 



ducks. Although presenting several anatomical peculiarities, 

 this genus is one containing several species of ducks, and 

 ducks not so very far removed from either the Teals, or the 

 Mallard, or perliaps Spatula. There is very little Goose, and 

 still less Swan, in the morphology of Dendrocygna, and for 

 what reason the genus has been placed between Philacte and 

 Olor in the ' Check-list ' it is difficult for me to understand. 

 Tn the first edition of his ' Manual ' Mr. Ridgway places 

 Dendrocygna the last genus in the duck-series where the 

 synopses of characters of the Anseres are set forth, while in 

 the part devoted to the diagnoses of species and genei'a these 



Fig. 1. 



Fio- 2. 



Fig. 1. — Right lateral view of the skull of Dendrocygna autnmnalis, 

 showing complete bony ring surrounding orbit. Pterygoids lost. 

 From a photograph by the author. § nat. size. 



Fig. 2. — Right lateral view of part of trunk-skeleton of same specimen. 

 ^ nat. size. 



Tree-Ducks are placed between the Swans and the Geese, as 

 in the ' Check-list.' They have, as I have just said, some 

 peculiar characters about them, and of these one of the most 

 interesting is the fact that they have complete bony rings 

 surrounding the orbits, as is the case in several genera of 

 parrots and some other birds. So far as I am aware it is the 

 only genus of ducks that presents this character — indeed, the 

 only anserine bird that has it. 



Coming to the Cranes and Rails we meet with an interesting 



