﻿310 ON THE CLASSIFICATION OF BIRDS. 



linaceous genera. Now this structure is carried on 

 also to Polyborus, and, amid the great diversity of the 

 species, in point of size and general appearance, although 

 not of structure, it becomes one of its most characteristic 

 marks. Polyborus is further distinguished from Ibycter 

 by the curvature of the upper mandible being much 

 the same as in the aberrant rapacious birds, by a much 

 greater length of wing, and by the smallness of the 

 external when compared with the internal claw : in 

 other respects there is such a marked affinity between 

 the two, that no link of the chain is wanting : the largest 

 species is Polyborus vulgaris, which is equal in size to 

 the goshawk. P. ochrocephalus (fig. 103.) is considerably 



smaller ; and an appa- 

 rently undescribed spe- 

 cies from Cayenne, now 

 before us, is scarcely 

 larger than the kes- 

 trel. Hitherto no spe- 

 cies of this group have 

 been found beyond the 

 V warm latitudes of 



America ; and probably 

 several others are confounded among the buzzards and 

 eagles. The typical species was long known to the 

 older ornithologists by the name of Brazilian kite — an 

 association which was founded in some truth ; for it is 

 by this group and Ibycter that the kites, generally so 

 called, are united to the eagles. The type, however, of 

 the milvine circle, in our opinion, is the genus Cymindis 

 of Cuvier, a group of birds entirely restricted to tropical 

 America, and of which four species are already known. 

 A very erroneous character has been assigned to Cy- 

 *niindis 3 which is neither possessed by this genus or by 

 any other in the raptorial circle with which we are ac- 

 quainted: the ce tarsi" have been termed semipalmated *, 

 a misprint, probably, for toes ; but in either case the 



* Cymindis — Tarsi breves semipalmati. — Zoological Journal) vol, i, 

 p. 337. 



