BIRDS OF NORTH AND MIDDLE AMERICA. 197 



Range. — Southern Mexico to Paraguay and southern Brazil. (Mon~ 

 otypic.') 



Notwithstanding resemblance to the Caciques and Oropendolas in 

 the broad and flattened basal portion of the culmen, the relationships 

 of this very strongly characterized genus are evidently much nearer 

 to Callothrus, with which it agrees in the remarkable neck-ruff (pres- 

 ent only in these two genera), and its parasitic habits. It differs from 

 Oallothrus., however, in its relatively much longer primaries with their 

 differently shaped inner webs, longer tail, relatively longer bill, with 

 broad and flattened mesorhinium, very much larger size, and other 

 characters. 



KEY TO THE SUBSPECIES OF CASSIDIX OBYZIVOEA. 



a. Plumage strongly glossed with bronze or violet. (Adult males.) 

 6. Metallic gloss bronzy throughout (inclining to violet only on pileum and under 

 parts. (Tropical South America, except Colombia. ) 



Cassidix oryzivora oryzivora (extralimital)* 

 66. Metallic gloss chiefly or wholly violet, 

 c. Back bronzy; violet tips to feathers of under parts narrower; larger (wing 

 averaging 201.2, tail 152, culmen 37.8). (Colombia, including Isthmus of 

 Panama; Veragua?; Costa Rica?; Nicaragua?.) 



Cassidix oryzivora violea (p. 197) 



cc. Back violet, like rest of plumage; violet tips to feathers of under parts 



broader; smaller (wing averaging 189, tail 146, culmen 37). (Southern 



Mexico to British Honduras. ) Cassidix oryzivora mexicana (p. 199) 



oa. Plumage not strongly glossed with bronze or violet. (Adult females and imma- 

 ture males.') 



CASSIDIX ORYZIVORA VIOLEA Bangs. 

 COLOUBIAN RICE GRACELE. 



Similar to G. o. oryzivora.,^ but decidedly larger, and plumage of adult 

 male glossed with violet instead of bronze (bronzy on back or back and 

 neck-ruffs only). 



Advlt male: — General color black, but feathers of head, neck, and 

 body more or less broadly tipped with glossy violet, this uniform on 

 head, neck, and back (the last inclining decidedly to bronzy), but on 

 the under parts forming a sharply defined terminal band or margin to 

 each feather, the basal black conspicuously exposed, these violet tips 

 becoming narrower posteriorly, and less distinct on rump than on 



'The single known species differentiated into three or more geographic forms or 

 subspecies. 



' \_Onolus] oryzivorus Gmelin, Syst. Nat., i, pt. i, 1788, 386 (Cayenne).— C[assi&i;] 

 oryzimra Cabanis, Mus. Hein., i, Sept., 1851, 194.— Cassidia; oryzivora oryzivora Bangs, 

 Proc. New Engl. Zool. Club, ii., June 30, 1900, 11 (in text). This form is introduced 

 into the key for sake of comparison. 



'The series of adult females and immature males is very imperfect, and therefore 

 I am unable to distinguish those of the several forms in the key. 



