106 



3IAE1NE EEPTILES OF THE OXFOEU CLAY, 



consists, so~ far as is known, of scapulae and coracoids only, no trace of any clavicular 

 arch having been found. The scapula and coracoid take about equal shares in the 

 formation of the glenoid fossa for the humerus. As in the vertebrae, the slenderness 

 or otherwise of the skull is reflected in this part of the skeleton, the coracoid and 

 scapula of St. leedsi, for example, being more slender than in St. durobrivensis. 



The scapula (sc.) is a bar of bone compressed from within outwards. At its upper 



Text-fig. 41. 



A. \ 1 





Eight side of shoulder-girdle of: A, Steneosaurus durobrivensis (E. 3701, | nat. size) ; 



B, Steneosaurus leedsi (B. 3S06, 4 nat. size). 



cor., coraccid ; /., coracoid foramen ; gl.f., glenoid fossa ; sc, scapula. 



end it is more or less expanded and in life was probably fringed with a suprascapular 

 cartilage. At its lower end it widens out and is thickened, bearing a large oblique 

 facet, forming the upper part of the glenoid cavity (gl.f.), and a terminal, elongated, 

 triangular surface for union with the coracoid : this latter surface is prolonged forwards 

 to the anterior angle of the bone. 



