CHENISCUS. 
There these birds are also associated with the Madagascar Nettapus 
auritus (Boddaert) in the genus Nettapus. 
The Australian birds, however, differ in having the bill shorter and 
not so deep, the nostrils smaller and placed nearer the base of the culmen, 
and longer legs and feet. The culmen in Nettapus exceeds the metatarsus 
in length, while the tail is more than half the length of the wing, and the 
upper tail-coverts extend to the tip of the tail ; in Cheniscus the upper 
tail-coverts do not hide the tail. 
The differences can be well estimated when it is noted that G. B. Gray, 
who was no genus splitter, not only admitted they were generically 
separable, but further placed them in different subfamilies. The present 
genus he re-named Microcygna, as he considered Cheniscus to be pre- 
occupied ; this genus name is an endeavour to express a suggestion of 
their aspect. Swainson also gave Anserella to this group with a similar 
reason. I would suggest that an examination of the anatomy of these 
forms will enable a better location than the present, which can only be 
considered a temporary expedient. 
VOL. IV. 
33 
