On a new genus ofPsittacidce. 387 



formantibus. Rectrices griseae, interne ad basin albae ; inferiores 

 ad basin albae apice grisescentes. Longitudo corporis^ 1 pes, 

 2 Y unc. ; alcB a carpo ad remigem Sdam, 9^^; caudce, 9 ; mandi- 

 bulce superioris ad froutem, -^^^ ad rictum, ^ ; inferioris r^^ ; 

 tarsi, 1 Tcy* 



Habitat in Afric4. 



** Remige 3tid longissimd. 

 FuRCATUs. N. albus, dorso medio, alis, rectricibusque nigris, 

 purpurea nitentibus. 



Rostrum nigrum: cera pedesqne flavi. Ptila purpureo-atra ; 

 tectrices inferiores albae : remiges secundariae, pteromata, scapu" 

 laresqne albo-variegatae. Longitudo corporis, 1 pes, 10 unc. ; 

 alee a carpo ad remigem Stianij i pes, 4 unc. ; caudce, 1 pes, 1 

 unc. ; mandibulce superioris, ad frontem, 1 ^^y ad rictum, 1 | ; 

 tarsi, 1 |. 



Habitat in Mundo Novo. 



There is a material difference in the construction of the wing 

 in these two birds. In the latter or the American species the 

 third quill feather is the longest, the first and second are marked 

 by an abrupt emargination in the inner web, and the second 

 third and fourth by a gradual decrease in breadth of the outer 

 web towards the apex. On the other hand the African species 

 has the second quill feather the longest, with a slight emargina- 

 tion only towards the apex of the first and second feathers, while 

 the outer webs of all are nearly even throughout. In consequence 

 of these characters N. Riocourii comes most nearly to the group 

 of Elanus, while N,furcatus shows an approximation to the true 

 Milvus. 



ON A NEW GENUS OF PSITTACIDiE. 



Among the primary groups or subfamilies into which the 

 "Parrots appear to be divided, two of the most conspicuous, as I 

 have elsewhere observed, are the birds which we familiarly call 

 Maccaws, and those commonly known under the name of long- 



2b2 



