461 



List of specimens in United States National Museum. 



Genus PHALCOBaENUS, Lafresnaye. 



a. Phalcohcenus. 



PhalcoM'niis L,AVR., in d'Orb. Diet, iii, 1843, 151. [Type, Aquila merjaloptera Meyex.] 



z?. Senex. 



Senev J. E. Gray, in Jard. & Selby 111. Om., u. s. 1839, pi. 24. [Type, Falco australis 



Gmel. ] 

 JElriorcliis Kaup, Class. Siiug. Vog. 1844, 124. [Same type.] 

 Relotriorcliis Eeich. Av. Syst. Nat. 1850, pi. xcviii. [Same type.] 



Osteology (of P. australis*). — Compared with that of Polydorus, the skull 

 is quite similar, but is relatively both broader than higher, and the nos- 

 trils entirely different, being circular and central. Premaxillary much- 

 less compressed throughout; frontal less turgid anteriorly, more inflated, 

 and with a deep median valley posteriorly ; lachrymals relatively and 

 absolutely much smaller; intermastoid width of the skull much greater; 

 j30sterior outline of the palatines gently rounded. Length of skull, 

 3.60 (1.90); breadth, 1.80; height, 1.30. 



Fterylosis. — Wing large, the primaries stiff and rather narrow, with 

 hard shafts ; third or fourth quill longest; outer four or five with inner 

 webs sinuated (almost emarginated on the outer) ; remiges, 25 (in P. me- 

 galoj)terus). Tail about three-tifths the wing, very slightly rounded or 

 almost even, the feathers broad, with firm webs and strong shafts. 

 Plumage in general full and rather soft (in the young very soft and 

 downy); loral and maxillary regions more or less naked, with scattered 

 bristles ; tibial plumes well developed. 



General external characters. — General form and appearance of Poly- 

 horus. Bill less compressed, and culmen more gradually curved, 

 the tip shorter; tomia very slightly lobed, and with the notch and 

 tooth obsolete. Nostril circular, central, and rimmed. Tarsus 1^ to 1§ 

 times the length of the middle toe ; lateral toes about equal ; the 

 anterior toes all webbed, the outer well developed, the inner very slight ; 



* Of this genus, we have only the skull of this single species. 



