316 INDIAN DUCKS 



Genus MERGANSER. 



The differences between Merganser and Mergus have ak-eady been 

 defined, and there is no other genus found, or hkely to be found, 

 in India with which it can possibly be confounded. 



According to Halvadori, there are seven species in this genus, but 

 he divides Merganser merganser into two species, and the Indian 

 form he designates Merganser comatus and distinguishes as being 



" somewhat smaller, the feathers of the crest thinner, narrower and 

 longer; the bill usually shorter; the male has tlie black edges of 

 the tertials broader, the lower baclv and rump paler grey, and usually 

 much freckled with white." 



The Eastern form had, however, already been given a name by 

 Gould in 1.S75, orientalis, which will have to be used instead of 

 comatus. 



No simpler key to the two Indian species can be found than 

 Blanford's which I give below ; — 



i\. Head and upper neck black glossed with green, (.\dult 

 males.) 



(('. Lower parts white throughout M. inavganscy. 



Ii' . Upper breast rufous with black marks M. Herrator. 



B. Head and upper neck rufous. (Females and non-adult 

 males.) 



(■'. Chin white, back grey -1/. iiwrijaii^cr. 



d'. Chin streaked with rufous, ijack brown J/, scrrator. 



