Thecodontosaums and Palteosaurus. 157 



No. 97 is an instructive fragment (fig. 7), showing the 

 articular end of the scapula in an uncompressed condition. 



Humeral articular 

 surface. 



Scapula of Pal<so$mirus. Erist. Mus. no. 97. ^ nat, size. 



The principal specimen, no. 89, is exposed on the internal 

 aspect, and consequently shows no indication of tlie articular 

 surface and only a slight film of the coracoid and a portion of 

 the impression from which the bone is lost. The scapula is 

 concave in length on the posterior surface, with a sharp ante- 

 rior border, wliich was reflected outward in the region in 

 which the thickening of the anterior crest of the scapula is 

 usually found. The bone does not appear to have been more 

 than b\ inches long ; it is 1^ inch wide towards the free end, 

 1 inch wide in tlie middle, 2yQ inches wide towards tlie 

 humeral articulation ; but it is fractured in front, and probably 

 had a width of 3^ inches. The coracoid is very imperfectly 

 indicated in this and the other specimens in which it appears 

 to be partially preserved. The substance of the coracoid is 

 Y^ inch thick, which is only half the thickness of the fractured 

 anterior margin of the scapula. There is some indication that 

 the surfaces of scapula and coracoid, which contributed to 

 make the articulation for the humerus, met each other at an 

 angle. Both these surfaces exceed an inch in length. There 

 is a slight eminence on the surface on the cast in the region 

 of the coracoid, which may indicate a foramen. It seems 

 probable that the scapulse here referred to belong to different 

 species ; and it might be anticipated that Palceosaurus will 

 have a comparatively large and strong articulation in the 

 shoulder-girdle when compared with Thecodontosaums. It is 

 possible that the bone no. 90 may pertain to the latter genus 



