318 MR. W. p. PYCRAPT ON THE [Apr, 15, 



X. Key to the Osteology of the Falconiformes. 

 A. Skull. 



Upper jaw more or less markedly hooked ; nostrils holorliinal, and when pervious, 

 associated with functional basipterygoid processes ; temporal fossae, when present, 

 coniined to the lateral aspect of the skull ; supra-orbital grooves absent ; \'omev 

 blade-shaped ; palate desmo- or schizognathous ; .in ossiculum lachrymo-palatinum 

 is never present. 



A. Palate indirectly desmognathous, being bridged bj-^ union of the septo-maxilLiry 



spurs with a horizontal plate developed by the ossified nasal septum ; olfactory 

 chamber of great size ; lachrymal fused with frontal ; nares pervious ; basi- 

 pterygoid processes functional ; vomer wanting C ATI! ARTiE. 



B. Palate indirectly desmognathous ; basipterygoid processes functional ; maxillo- 



palatiues with an enormous antrum of Highmore ; lachrymal with a verj' large 

 supra-orbital process closelj^ applied throughout its whole length to the frontal, 

 and with its descending process reaching to the quadrato-jugal bar. 



SERPENTARII. 



G. Palate directly or indirectly desmognathous or schizognathous ; nares impervious ; 

 basipterygoid processes vestigial or wanting ACCIPITRES. 



Key to the Families of the Accipitres. 



A. Vomer terminating anteriorly in a more or less conspicuous olive-shaped swelling, 



closely applied to the maxillo-palatine processes. Palate directl3' desmognathous ; 

 antorbital plate (prefi-ontal) largely developed and with outer border closely 

 applied to or fusing with the lachrymal ; lachrymal without superciliary 

 plate; squamosal prominence strongly developed; nostrils with a very small 

 circular or slit-like aperture ; ventral aspect of premaxilla with a median bony 

 ridge ; mandible with a ramal vacuity Falcohid.^. 



B. Vomer never expanded anteriorly, and never applied to the under surface of the 



maxillo-palatines ; palate indirectly desmognathous, or schizognathous ; ant- 

 orbital plate (prefrontal) generally tongue-shaped, often much reduced, or 

 articulating, or even fusing by its free end with the distal extremity of the 

 lachrymal; nostrils slit-like or pear-shaped, and fully exposing the nasal 

 septum ; lachrymal generally provided with a superciliary plate ; squamosal 

 prominence not greatly developed Buteonidje. 



Key to the Suh-fcmiilies of the Falconidee. 



A. Supra-orbital process of lachrymal extending backwards beyond middle of orbit ; 



temporal fossa heart-shaped Falconincs. 



B. Supra-orbital process of lachrymal not extending as far as the middle of the 



orbit; temporal fossa elliptical Folyhorince. 



B. Sternum and Pectoral Girdle. 



Corpus sterni very large, relatively to the size of the girdle, oblong, and with 

 relatively small anterior lateral processes which bear facets for the articulation of 

 the anterior sternal ribs ; posterior border entire, notched or fenestrated, but the 

 posterior lateral processes are never very large ; articular siu-faces for sternal ribs 

 extend up to or beyond the middle of the sternal plate ; coracoid grooves wide, but 

 shallow, and bordered above by a well-marked " lip " ; coracoids slightly overlapping 

 or only touching one another, and with a well-marked ^rocessMS lateralis hasalis ; 

 acrocoracoid very large; furcula U-shaped and very broad, with a feebly developed 

 hypocleideum. 



A. Corpus sterni with metasternum produced into a point, bounded by a pair of 



notches ; furcula articuhating with the antero-inferior angle of keel ; acro- 

 coracoid not affording an articular surface for furcula SERPENTARII. 



B. Corpus sterni with posterior border with two pairs of notches, the outer pair 



sometimes becoming closed to form fenestra; ; keel very deep, extending back- 

 wards to extreme end of sternum ; coracoid grooves divided from one another in 

 the middle bv a strong ridge ; acrocoracoid without articular facets for furcula. 



CATHARTyE. 



