ORNITHOLOGICAL CLUB. 71 



theres^ and similarly divides the subfamily Buteonince into three " groups," 

 which he calls Pandiones, Perms, and Buteones. While Mr. Ridgway en- 

 deavors to make use of all available characters as the basis of his divis- 

 ions, his classification is based primarily upon the character of the coracoid 

 apparatus, particularly as to whether the scapular process of the cora- 

 coid is produced forward so as to meet the clavicle, or is separated from it 

 by a wide interval ; and also upon the character of certain bones of the 

 skull, especially the supra-maxillary, the nasal, and the superciliary pro- 

 cess of the lachrymal, of which parts are given numerous outline illustra- 

 tions. Whether Mr. Ridgway has quite hit the " natural arrangement " 

 here aimed at, and whether he has not placed undue value upon the modi- 

 fications of the scapular process of the coracoid, are matters respecting 

 which there is evidently room for honest differences of opinion. 



This paper, which closes with a synopsis and diagnoses of the genera 

 and subgenera of the Polybori, is followed a few months later by his 

 " Monograph of the Polybori." * This is strictly an American group, of 

 very peculiar appearance and habits. They are chiefly tropical in their 

 distribution, inhabiting all parts of South America, where they most 

 abound, and do not extend northward beyond sub-tropical limits, a single 

 species only (the Caracara, Polyborus cheriwmj) reaching the southern bor- 

 der of the United States. About ten species only are recognized by Mr. 

 Ridgway, which he refers to four genera, namely, Polyborus, Phalcobcenus, 

 Milvago, and Ibycter. The more important generic characters are illus- 

 trated by outline figures, and the various phases of plumage of the species 

 are quite fully described. 



A little later, under the general title " Studies of the American Falcon- 

 idce" t Mr. Ridgway continued his account of the American Falconidce, 

 descriliing in detail sixteen genera and some forty species, besides a num- 

 ber of varieties. Thirteen species are referred to the single genus Nisus 

 (=Accipiter of many authors), while twelve other genera have each but a 

 single species. A few only of the species described in this paper are 

 North American. These are, ^^ Nisus" cooperi, " N" fuscus, Onychotes 

 gruberi, Anterior unicinctus var. harrisi, and Elanoides forficatus, only three 

 of which range very far into the United States. 



Mr. Ridgway also, in the mean time, published a paper " On Nisus 

 cooperi (Bon.) and N. gundlachi (Lawr.)," J in which he maintains the en- 

 tire specific distinctness of " N." gundlachi, which had been previously by 

 several authors, including Mr. Ridgway himself, referred to " N." cooperi. 



This paper is immediately followed by another, " On the Buteonine 



* Studies of the American Falconidce: Monogi-aph of the Polybori. Bull. 

 U. S. Geol. and Geogr. Survey of the Terr., Vol. I, No. 6, pp. 451-473, pis. 

 xxii-xxvii, February 8, 1876. 



t Bull. U. S. Geol. and Geogr. Survey of the Terr., Vol. II, No. 2, pp. 91 - 

 182, pis. xxxi, xxxii, April 1, 1876. 



X Proc. Acad. Nat. Sci. Phila., 1875, pp. 78-88. 



