172 



MARINE EEPTILES OP THE OXFORD CLAY. 



end. Ventrally, there is a broad expansion terminating below in a convex border ; this 

 distal expansion is very thin. The coracoid in this genus is distinguished from that of 

 Steneosaurus by the greater expansion of the distal end and the relatively greater width 

 of the neck. 



Fore Limb (text-fig. 70, A). — The humerus is a proportionately small bone, much 

 compressed from above downwards. The head (h.) is a strongly convex surface, oval 

 in outline and nearly at right angles to the long axis of the bone, not being directed 

 backwards as in Steneosaurus. Beneath it the flattened shaft widens out to the 

 deltoid crest (d.c), which forms a sharp prominence directed somewhat downwards 



Text-fig. 70. 



Shoulder-girdle aud fore limb of Metnorhynchus sttperciliasum : A, right fore limb (incomplete) ; 

 B, right coracoid and scapula. (R. 3016, | nat. size.) 



cor., coracoid ; d.c, deltoid crest ; gl.f., glenoid fossa ; h., head ; n., notch ou coracoid ; r., radius ; 



sc, scapula ; ?<., ulna. 



and situated a little above the middle of the shaft. Beneath the deltoid crest the 

 shaft narrows gradually to the distal articular surface, which is strongly convex, but is 

 not divided into an outer and an inner condyle. On the dorsal surface, in the 

 neighbourhood of the deltoid crest, there are strong rugosities for muscle-attachment, 

 and there are also roughened surfaces on the anterior border between the deltoid 

 crest and the distal articulation, which is in the same plane as the head, not making 

 an angle with it as in Steneosaurus. 



