THE IBIS. 
THIRD SERIES* 
No. XXI. JANUARY 1876* 
I. —Second Thoughts on the Genus Micrastur. By Robert 
Ridgway, of the Ornithological Department, U.S. National 
Museum, Washington* 
Having recently examined the entire series of the smaller 
members of this genus contained in the collection of Messrs. 
Salvin and Godman, sent to me for that purpose, I have been 
induced, to modify to some extent my views given in the 
‘ Proceedings 5 of the Boston Society of Natural History for 
1873. 
The series is a splendid one, and has, I think, enabled me 
to get the right idea of the species of this exceedingly per¬ 
plexing group. 
Setting M. melanoleucus (sive “ semitorquatus ”) and M. 
mirandoltii aside, as being distinct enough to need no notice 
in connexion with the smaller species, I identify the names 
of previous authors as follows :— 
Sparvius ruficollis, Vieill., = M. ruficollis, Scl. & Salv., rufous 
phase, adult. 
Sparvius gilvicollis, Vieill.*, —M. leucauchen, Scl. & Salv., 
* This cannot, according to the terms of the diagnosis, he M gilvi- 
collis, Scl. & Salv., if the latter = my concentricus, which = concentricus of 
SER. III.-VOL. VI. B 
