52 FALCONlDiE. 



three species or races which it contains spreading over nearly the whole of the warmer 

 portions of the region. 



In Mexico and Central America we find a fairly well-marked race distinguished by 

 the blackness of its plumage from either of the others of the South-American continent. 

 It represents the genus in the north as far as Mazatlan in Western, and Cordova in 



Eastern Mexico. 



Regarding the affinities of this genus, Mr. Eidgway has recorded that the tibio- 

 tarsal joint is flexible both forwards and backwards, as in the African genus Polyhoroides, 

 and on this and other grounds considers that the two forms are allied — a view held by 

 Gumey both prior to Mr. Ridgway's observations and subsequently. 



The position of these genera must remain uncertain until such time as more complete 

 dissections have been made and comparisons instituted. In the meantime, though we 

 leave Geranospizias in the Accipitrinse, we do so with a conviction that it will be 

 ultimately removed elsewhere, as neither its structure, so far as we know it, or habits 

 are in conformity with the true Accipitrinse. 



The genus is described by Mr. Ridgway as follows : — " Form very slender, the wings 

 and tail very long, the head small, bill weak, and tarsi extremely long and slender. 

 Outer toe very much shorter and weaker than the inner, and about equal in length to 

 the posterior, its claw disproportionately small and weak. Tibio-tarsal joint flexible 

 both backwards and forwards. Secondaries much developed, reaching nearly to the 

 end of the primaries, and very broad. Bill much as in Nisus [i. e. Accipiter] ; nostril 

 obliquely horizontal, oval. Tarsus about two and a half times as long as the middle 

 toe, with frontal and posterior series of broad transverse scutellae, these being often fused 

 into continuous plates ; claws normal. Tibial feathers short and close, not plume-like. 

 Wing long, but the primaries not much longer than the secondaries, the fourth to the 

 sixth quills longest, the first the shortest and much bowed ; outer six with inner webs 

 sinuated. Tail long, nearly equal to the wing, rounded, the feathers very broad." 

 (Ridgway, Pr. Bost. Soc. N. H. xiv. p. 276.) 



We have no means of ascertaining the relative positions of the ends of the coracoid, 

 scapular, and clavicle in this genus, which should have a determining influence in fixing 

 the position of Geranospizias. 



1. Geranospizias niger. 



Isclmosceles niger, Du Bus, Bull. Ac. Brux. xiv. p. 102 ' ; Esq. Orn. t. 16 ^ ; Salv. P. Z. S. 1870, 



p. 216 \ 

 Geranospiza nigra, Scl. & Salv. P. Z. S. 1870, p. 838 * ; Lawr. Bull. U. S. Nat. Mus. no. 4, p. 39 '. 

 Geranospizias niger, Sharpe, Cat. Birds Brit. Mus. i. p. 82°; Sumichrastj La Nat. v. p. 235'- 



ZeledoD, An. Mus, Nac. Costa Rica, 1887, p. 127 ' ; Salv. Ibis, 1889, p. 375 ' ■ 1890 



p. 89". 

 Geranospiza gracilis, Scl. P. Z. S. 1856, p. 285 ". 



