1826.] Spix, Avium Braziliensium Species Nova. 285' 



tinga, t. 64), 1. 1, b. and the Kitelike eagle (Aquila Milvoides), 

 a kind of illustration of the engraving which we have never 

 before observed in natural history plates. The best idea of it 

 will be conveyed by considering it as an exact lithographic 

 representation of an excellent wood-cut; and every one who 

 has seen the works of Bewick must be ready to allow that this 

 kind of engraving is well adapted for representing this order of 

 animals. It appears to be done by covering the stone with ink 

 in the form of the bird, and then scraping off those parts which 

 are wanted to be light, and it leaves the outline sharp and dis- 

 tinct, which is not the case with lithography in general. Mr. 

 Schmidt has only used this kind of lithography for the dark parts 

 of birds, although there appears no reason why it should not, like 

 wood-cuts, equally represent the more delicate tints ; he has 

 often used it in conjunction with the other kind, as may 

 be observed in the Caracara (t. 1, a). The Tezoura, t. 8, b. 



The present volume only contains the Raptorial and part of the 

 Passerine birds. Dr. Spix divides the birds into natural groups 

 without taking any notice of the orders ; and under the famihes 

 he gives an abridged account of the habits of the birds which 

 are referable to them, which is the only notice that he takes of 

 their manners, except in a very few instances. 



The first family he calls Falcones, which appears to compre- 

 hend the Falcons and Vultures of Linnaeus. In this family, he 

 describes three new genera, as follows : 



1. Gymnops. " Rostro subelongato gallinaceo, baud alto, 

 subcylindrico, circa basin, praecipue ante oculos nudo, apice 

 subadunco, oblique descendente; naribus rotundis ; collo 

 exserto; tarsis breviusculis; alis cruciatis; cauda sequali vixbre- 

 vioribus ; unguibus compressioribus, gracilioribus." 



This genus is very nearly allied to the Polj/bori of Vieillot, 

 which M. Spix also adopts : it contains four species, amongst 

 which are the Falco formosus of Latham, the type of Vieillot's 

 genus Ibycter; and Falco Ater, the type of the genus Daptrius 

 of the latter. 



2. MiLVAGO. Habitu milvo, rostro Gymnopi simillimo, 

 breviore, acuto, minus adunco, et circa oculos multo minus 

 nudo; alis longioribus, caudam breviorera, aequantibus; naribus 

 rotundis ; gula non nuda. 



This genus is also very nearly allied to Polyborus, and is, 

 perhaps, the Daptrius of Vieillot; but in fact Cuvier appears to 

 be right when he refers them all to Caracara : it only contains 

 one species, M.oc]irocephalus,\\\i\c\\\^ in the British Museum. 



3. BiDENS. Tinnunculoides, exiguus; pedibus gracilioribus, 

 rostro brevi subcompresso plus minusve, bidentato ; alis crucia- 

 tis, Cauda brevioribus. 



This genus is here first separated from the falcons, to which it 

 is considerably allied, but the name was long ago employed by 



