SAUROPTEEYGIA. 



247 



part answering to the episternum of lizards 

 the bone is short and straight, 

 somewhat flattened ; the thick 

 articular end, which forms the 

 shortest ray, is subequally di- 

 vided by the articular surface 

 for the coracoid, and that for the 

 head of the humerus. 



The coracoids are remark- 

 able for their excessive expan- 

 sion in the direction of the axis 

 of the trunk, extending from 

 the abdominal ribs forward, so 

 as to receive the episternum, 

 which is wedged into their an- 

 terior interspace. The median 

 borders meet and unite for an 

 extent determined by their de- 

 gree of curvature or convexity, 

 which is always slight. The 

 coracoids unite anteriorly with 

 the clavicles, as well as with 

 the episternum ; laterally they 

 articulate with the scapula, to 

 form the glenoid cavity for the 

 humerus. 



The episternum has the 

 same general form as the me- 

 dian pieces of the abdominal 

 ribs, being, like those pieces, 

 a modified haemal spine, only 

 more advanced in position ; the 

 lateral wings or prolongations 

 are broader and flatter ; the 



The body of 



