MUE.ENOSAIJEUS. 



109 



while the middle of the posterior border may either bear a similar rounded notch 

 {M. dict'obriveusis, PI. V. fig. 10 ; M. p!at//clis, PL VI. fig. 3 ; text-fig. 68) or it 

 may be produced back into a short pointed process (1 31. leedsi, PI. VI. fig. 6 ; text- 

 fig. 62) ; in the former case the notch may form the anterior border of the interscapular 

 foramen {i.s.f., PL VI. fig. 3; text-fig. 68). The variations of the shoulder-girdle in 

 this genus will be noticed under the difi'erent species into which it has been found 

 desirable to distribute it. 



Text-fig. 62. 



Shoulder-girdle of Mwmnosaurus 'lleedsi, (K. 3704, -J nat. size.) 

 cor., coracoid ; gl., glenoid cavity ; i.cl., iuterclaviele ; i.s.f., interscapular foramen ; sc, scapula. 



■ The scapuloe (sc, PL VI. fig. 3 ; text-figs. 62, 67, 68), as in the other genera of the 

 Elasmosauridse, are triradiate bones, each consisting of a posterior arm uniting with 

 the antero-external angle of the coracoid, a dorsal arm extending towards the vertebral 

 column, and a ventral expansion which, in the adult animal, meets its fellow in the 

 middle line in a deep symphysial surface, which extends back to meet the anterior 

 median prolongations of the coracoids. The posterior bar is thickened at its extremity, 

 v/here it bears two facets, one for union with the coracoid, the other forming the 

 anterior part of the glenoid cavity. The fiirsit of these facets looks backwards and 



