OSTEOLOGY OF BIRDS I 27 



In his Hand-List of Birds [July 6, 1899. 1:241-79], Dr 

 R. Bowdler Sharpe places the Cathartidae in a separate group 

 (Order 24), and does not include them with the Accipitres, although 

 he admits the \ ulturidae to that assemblage. For the 500 and over 

 existing and extinct forms of these birds of the world's avifauna, 

 now known to science, and recorded in the Hand-List, Dr Sharpe 

 proposes the following classification. 



ORDER (XXV) SUBORDERS FAMILIES SUBFAMILIES 



Accipitriformes 



I Serpentarii I Serpentariidae 



f I Vulturidae 



I f I Polyborinae 



II Accipitres .t 17 1 ■ 1 J "' ^ccipitrinae 



II ralconidae -< 3 Buteonmae 

 [ 4 GypaiJtinae 



L 5 Aquilinae 

 III Pandiones 



It will be observed that Dr Sharpe makes no families under his 

 Pandiones (Suborder 3), including in it only the two genera 

 Pandion and Polioaetus. The order (26) next following his Ac- 

 cipitriformes is for the owls (Strigiformes), wdiich is a far more 

 natural arrangement for the latter than this eminent ornithologist 

 gave us in his former taxonomic scheme of the class, in which he 

 included the owls in his order Accipitriformes [Recent Attempts to 

 Classify Birds, p. 78, 79]. 



OSTEOLOGICAL CHARACTERS OF THE ACCIPITRES 



Including some negative characters 

 Accipitres 



Birds, which exhibit in their skulls a more or less powerfully 

 hooked superior osseous mandible ; having the length of a pterygoid 

 not greater than the longest transverse diameter of the basitemporal ; 

 lacrymal bone for the most part composed of a firm, compact bony 

 tissue. Os furcula U-shaped and always complete and strong; 

 pneumatic. Fibula always reaches to lower third of shaft of 

 tibiotarsus ; basal joint of third toe equals or exceeds the transverse 

 diameter of the summit of the tarsometatarsus. 



I Milvidae {Including the Milvinae) (Rostrhamus not ex- 

 amined). Osseous nasal septum generally entire; superior osseous 

 mandible not laterallv toothed. Supraorbital process of a lacrymal 

 may be short (Elanoides) or long (Ictinia, Elanus) ; it may 

 (Ictinia, Elanus) or it may not (?) (Elanoides ?) have a terminal 

 acccssorv piece; it may articulate with pars plana (Elanus) or it 

 may not (Elanoides). They arc dcsnwgnathous (Ictinia) or 

 nondcsmognathous (Elanus). Vomer present. Basipterygoidal 

 processes are present (Elanus) or absent (Ictinia) ; and the post- 



