Mr. R. B. SkarjH''s Catalogue of Accipitres. 477 



Wing from Middle 



carpal joint. Tarsus. toe, s. ii. 



in. in. in. 



Male, taken from Sclater and Salvin's 



' Exotic Ornithology ' G-6 1-9 



Male, in Noi-wich Museum, from 



Bahia 64 1-7 M 



Female, in Norwich Museum, loca- 

 lity unknown 8 2 1 '4 



Female, in Messrs. Salvin and God- 

 man's collection, from East Brazil 7'6 1-8 1-4 

 Female, in the same collection, from 



Bahia 76 lO 1-3 



It would appear from the above that the average size of A. 

 erythrocnemis is somewhat less than than that of its western 

 congener, A. ventralis, of which species I have recently mea- 

 sured eight presumed males and the same number of pre- 

 sumed females, with the following results : — 



Wing from Middle 



carpal joint. Tarsus. toe, s. u. 



inches. inches. inches. 



Males 6-7 to 6-9 1-9 to 2 l-lo to 1-3 



Females 7-9 to 8-7 2-1 to 2-2 1-25 to 1-5 



The excess in average size of A. ventralis over A. erythro- 

 cnemis, though not very great, is yet of importance as a guide 

 in distinguishing the two species, and the more so, as speci- 

 mens of A. ventralis occur which are almost precisely similar 

 in the coloration and markings of their under surface to the 

 adults of A. erythrocnemis, the breast and abdomen being 

 barred with alternate transverse bands of white and greyish 

 brown, though the upper surface is always rather darker than 

 in the adults of A. erythroctiemis. 



I think it is certain, from a comparison of a series of spe- 

 cimens, that this plumage of A. ventralis intervenes between 

 the earliest dress, which ]Mr. Sharpe designates as " young," 

 and that which he correctly describes as '' adult." Thi'ee such 

 females from New Granada are preserved in the Norwich 

 Museum ; and a male, passing out of this intermediate stage 

 into the adult plumage, and also from New Granada, is in 

 the collection of Messrs. Salvin and Godnoan : in this speci- 



2 M 2 



