In this subfamily the bill is not depressed but is subconical or subcylindrical; the tip is hooked; the lamellae are replaced by tooth-like non-pliant serrations- the tarsi are placed very far back, the feet are large, the hind toe well developed and with a broad lobe. There are two genera represented in India.
Key to Genera.
A. Culmen not longer than tarsus; tail of sixteen feathers………… Mergellus, p. 466.
B. Culmen much longer than tarsus; tail of eighteen feathers………… Mergus, p. 468.