STEXEOSAURUS. 



109 



The ulna (text-fig. 42, E, F, u.) is greatly expanded at the proximal end, the 

 expansion forming a prominent olecranon angle (ol.). The facet for the humerus (h.s.) 

 is not almost terminal, as in the recent Crocodiles, but lies nearly parallel with the 

 long axis of the bone. From the olecranon angle the posterior border of the bone is 

 at first gently convex, then towards the distal end it becomes concave ; the anterior 

 border from the humeral facet to the distal end is concave. The distal articulation 

 consists of a larger preaxial and a smaller postaxial convexity connected by a ridge ; 

 the preaxial projects below the postaxial portion. 



The bones of the fore foot are not well known. 



Text-fig. 43. 



Outer side of the left half of the pelvic girdle of Steneosaurus leedsi. (R. 3S06, \ nat. size.) 



a.a., anterior angle of ilium ; acet., acetabulum ; a.p.i., anterior process of ischium ; 

 it., ilium ; is., ischium; pu., pubis. 



Pelvic Girdle and Hind Limb (PL VII. figs. 7, 8 ; text-figs. 43-47).— The pelvis 

 (text-figs. 43, 44) is formed by the usual three pairs of bones — the ilia, ischia, and 

 pubes. 



The ilium (il.) in its general form much resembles that of the recent Crocodiles. 

 The upper border is sharp and nearly straight ; anteriorly it ends in the point of the 

 prominent anterior angle («.«.), which is much more strongly developed than in recent 

 types. The ventral face of this prominence is strongly concave and passes below by a 

 sharp curve into the wide convex anterior border of the body of the bone, which 

 terminates ventrally in a broad roughened prominence. On the outer face of the bone 



