THE PTEEOSATTEIA. 269 



and thus gives rise to a supra-temporal fossa. The post- 

 frontal and the jugal unite behind the orbit, in Lacertilian 

 fashion; and both the upper and the lower jaws contain 

 teeth. The sclerotic is supported by a ring of bones, as in 

 many other Sauropsida. 



The scapula and the coracoid are whoUy unlike these 

 structures in any other Sauropsida, but are extremely 

 similar to the same parts in birds, and indeed to the 

 shoulder gii'dle of the less reptilian Carinatce. The scapula 

 is slender and blade-like, and its long axis is inclined, at 

 less than a right angle, to that of the coracoid. The 

 glenoidal surface is cylindroidal, concave from above down- 

 wards, convex from side to side. The coracoid, elongated 

 and comparatively narrow, is devoid of fontanelle, epico- 

 racoid, or procoracoid. 



No trace of any clavicle has been discovered. 



The humerus has a great deltoid ridge or process. The 

 radius and iilna are equal in size and separate. There are 

 four distinct metacarpal bones, that on the ulnar side being 

 very much stronger, though not longer, than the others. 

 Another styliform bone attached to the carpus does not 

 appear to have belonged to the metacarpal series. The 

 radial metacarpal bears two phalanges ; the second, three ; 

 the third, four, so that these represent the poUex and 

 the succeeding digits of the Lizard's manus. The ter- 

 minal phalanx of each of these digits is strong and 

 curved, and was doubtless ensheathed in a horny claw. 

 The fourth, like the corresponding digit in the Crocodile, 

 has four phalanges, the last of which is straight and bears no 

 nail. But these phalanges are enormously elongated and of 

 great relative strength. A strong process projects from the 

 dorsal side of the proximal end of the first phalanx, and 

 doubtless gave attachment to the tendon of a correspond- 

 ingly powerful extensor muscle. The articular sm'face 

 below and behind it, is concave, and plays over the convex 

 distal pulley of the fourth metacarpal. 



The pelvis is remarkably small. The ilia ai"e elongated 

 bones, produced both anteriorly and posteriorly, as in Birds; 



