436 BIRDS OF BRITISH GUIAKA. 



Genus MICEOPHILA Chubb. 



Microplila Chubb, Ann. & Mag. Nat. Hist. (ser. x.) p. 192, Feb. 1921. 

 Type M. castaneiveniris (Cab.). 



Fig. 16J;. — Miorophilu castanelventris. 



The chief characters o£ the species that I suggest for separation 

 as a new genus, are the straight • culmen, not arched or semi- 

 circular as in Sporophila, and the more rounded tail. Its small 

 size and peculiar coloi'ation also help to distinguish it. Type 

 M. castanelventris (Cab.). 



Key to the Species. 



A. Lower back, rump, and upper tail-coverts 



grey like the greater portion of the 



upper surface M. castanelventris, p. 436. 



B. Lower back, rump, and upper tail-coverts 



bright chestnut in contrast to the rest 



of the upper surface M. minuta, p. 438. 



626, Microphila castanelventris. 



Chestnut-bellied Seed-batbe. 



Sporophila castanelventris Cab. in Schomb. Reis. Guian. iii. p. 679, 

 1848 ; Beebe, Our Search' for a Wilderness, p. 171, 1910 ; Brabourne 

 & Chubb, B. S. Amer. i. p. 365, no. 3743, 1912 ; Beebe, Tropical 

 Wild Life in British Guiana, p. 136, 1917. 



Spermophila castanelventris Salvin, Ibis, 1885, p. 214 (Bartica Grove) ; 

 Sharpe, Cat. B. Brit. Mus. xii. p. 108, 1888 (Bartica Grove); 

 Quelch, Timehri (2) v. p. 84, 1891 (Georgetown). 



" Blue-hacked Seed-eater" [Beebe). 



Adult male. General colour of the upper surface dark ash-grey 

 including the crown of the head, entire hack, scapulars, and upper 

 tail-coverts ; upper wing-coverts, bastard-wing, and innermost 

 secondaries black margined with ash-grey ; primary-coverts and 



