Key to the S'pecies. 
A, Smaller ; outer web of the first primary white ; 
long fiank-feathers black, with a central pear- 
shaped white spot T. ventralis, p. 227. 
B. Larger; outer web of the first primary uniform, 
like the rest of the quills ; long fiank-feathers 
black, broadly tipped with white . . . . T. mortieri, p. 223. 
222 
