TEOCHILIDiE.] OSTEOLOGIA AVIUM. [MELLISUGIN^. 



Order II. VOLITORES. 



Fam. 1. TROCHILID-E. 



Subfam. 1. Mellisugin^e. 



Patagona, G. R. Gray. 

 Gigas, Vieill. 

 Type of Volitores. 



Cranium of moderate size ; a deep and broad depression between the orbits, which is 

 carried backwards to the occipital protuberance, where it divides and is carried down- 

 wards on each side to the base of the skull. Orbits large, slightly oval ; the edges entire ; 

 the margins slightly rerlexed ; orbital septum entire. Palatine bones consisting merely 

 of two elongated and narrow plates, pointed posteriorly at their junction with the inter- 

 articular bones, with the edges slightly bent downwards, united for their anterior half, 

 and then divaricating. Interarticular bone slightly bent backwards in the centre ; 

 occipital protuberance very large. Foramen magnum round, placed obliquely. 



Sternum long, of moderate width posteriorly, very narrow anteriorly, very slightly 

 longitudinally convex ; a spinous process behind the junction of the coracoids. Keel 

 very deep ; inferior edge arched, and carried to the extremity of the sternum ; anterior 

 edge much excavated, not receding ; articulation with the coracoids effected by means 

 of a ball and socket joint, the ball of which is upon the sternum. Posterior margin 

 entire, rounded. 



Pelvis very broad and short, but narrow; the ilium not overhanging the ischium, 

 which inclines outwards and downwards from the ilium to the os pubis ; obturator and 

 ischiadic foramina of moderate size ; ribs long, placed very obliquely, and carried far 

 backwards. 



Humerus very short and strong; muscular processes very highly developed; ulna 

 short, nearly straight; radius slightly bent. Metacarpus very long; division between 

 the two bones composing it very slight ; the posterior one anchylosed to the anterior 

 for the anterior third of its length; first phalanx narrow at proximal extremity, and 

 expanded at its distal by reason of the divarication of the two bones composing it ; a 

 bony plate unites them together; terminal phalanx long; furculum very small, not 

 approaching the sternum, slightly flattened; coracoids straight, slightly flattened, 

 expanded at their lower extremity, and furnished with a socket, which corresponds with 

 the ball on the sternum. Scapula very long, flat, expanded and bent downwards at the 

 extremity. Leg bones weak ; femur very straight ; radius extending for about one-third 

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