112 INDIAN DUCKS 



Subfamily ANATIN^. 



Key to Genera. 



A. Lower portion of tarsus in front with small 



reticulate scales Deiidrocuciui, p. 93. 



B. Lower portion of tarsus in front with a row of 



transverse scutellm. 



a. Speculum wanting Mannanmctia, p. 202. 



h. Speculum always present. 



f/'. Outer web of inner secondaries chestnut, 

 rt". Colouration pied, chestnut, black and 



white Tadonia, p. 109. 



/'^. Colouration all rufous-chestnut of dif- 

 ferent shades, except on quills . . Casarca, p. 114. 



6'. Outer webs of inner secondaries not 



chestnut. 



cl Bill spatulate Spalida, p. 196. 



fi'^ Bill not spatulate. 



a'. Uppei- wing-coverts blue or grey-blue Qncrqucdula, p. 188. 



I?. Upper wing-coverts not grey-blue. 



a\ Tail long, with the central tail- 

 feathers acuminated and extend- 

 ing well beyond lateral tail- 

 feathers Dafila, p. 181. 



h\ Central tail-feathers not elongated, 

 and tail moderate in length. 



ft'. Bill broad, about the length of 



the head yl»a.s, p. 123. 



/)'. Bill not very broad and shorter 

 than the head. 



rt". Upper and lower tail-coverts 

 extending beyond end of 

 rectrices Emu'ttii, p. 143. 



