INDIAN DUCKS AND THEIR ALLIES. 603 



being blown. The texture is smooth, fine and close, but the shell is 

 rather fragile for the size of the egg, and this would appear to be the 

 case with most pochards' eggs. 



In shape they are either rather long or rather broad ovals, very 

 regular in shape, and with both ends practically the same in size. 



The majority of birds breed in May and early June : very few, it 

 would seem, as early as the end of April. The number of eggs is most 

 often eight to ten, but they vary from only six to at least fourteen on a 

 few occasions. 



Genus NYROCA. 



The genus Nyroca, according to Salvador! who divides Fuligula from 

 Nyroca, contains ten species, of which three are found in India. Nyroca 

 differs from Netta in the formation of the bill and lamellse, the latter 

 having them larger, more prominent and closer together than the 

 former. 



The genus is a cosmopolitun one, and amongst its ten species con- 

 tains what is, perhaps, our most common duck, namely, Nyroca 

 africana (or ferruginea), the White-eye. 



Key to the Species, 



(a) Back and scapulars distinctly barred or vermiculated.../mwa ^ 



{b) Back and scapulars merely speckled. 



a'. Head and ueok dull chestnut or bay africana 



b'. Head and neck almost black baen$ 



(c) Upper back and head rufous-brown, scapulars slightly 



vermiculated, no white speculum .ferina^ 



(d) No vermiculations on upper plumage : a white 



speculum. 



a". Head and neck rufous-brown africanaQ 



b". Head and neck more or less mixed with 



blackish on the sides ..baeri9 



In addition, baeri may be discriminated from africana by its larger 

 size and proportionately larger bill. 



31. Nyroca b^erina. 

 The Pochard or Dun-bird. 

 Aythya ferina, Jerdon, " Birds of India," III, p. 812 ; Hume, *' Str. 

 Feath.," I, p. 264 ; Adams, ibid, p. 409 ; ibid, II, p. 341 ; Butler* 

 ibid, IV, p. 30 ; V, p. 234; Ball, ibid, VII, p. 232. 



