Manchester Memoirs, Vol. Iw. (1909), No. 4. 23 



Our type also resembles in its pectoral girdle 

 P. Conybeari, as restored by Sollas. 



The scapula of our specimen is, however, quite unique 

 in its fore and aft direction and its downwards slope in 

 front. 



The characters of the vertebral column separate our 

 type from Plesiosaurns as typified by P. dolichodeirus 

 and from the reptiles placed in Thaumatosaurus by 

 Lyddeker. 



There is no resemblance to any genus with the 

 Elasmosaurian type of pectoral girdle. 



There is, in fact, no described genus which will hold 

 the species. I therefore propose to call it Sthenarosaurus 

 Dawkinsi from (jOevafjoc (strong) and Prof Wm. Boyd 

 Dawkins. 



Sthenarosaurus may be defined as follows : — 



Plesiosaurs with the neck tapering from back to front. 

 Cervical vertebrae with concave anterior face to the centra, 

 prae- and post-zygapophyses united, forming a table from 

 which the neural spine rises abruptly in the anterior, and 

 more gradually in the posterior cervicals ; anterior neural 

 spines weak and placed far back. 



" Pectorals " with short stout neural spines leaning 

 far back. 



Cervical ribs double-headed. 



Pectoral girdle with short coracoids, strong scapulae 

 very widely separated anteriorally and pointing down- 

 wards. Clavicular arch robust containing an interclavicle, 

 with a wide anterior notch and a small posterior tag. 



Pelvic girdle with large square pubes and short 

 ischia meeting medially so as to leave two obturatores 

 foramina. 



Type species Sthenarosanms Daivkinsi, no v. sp. 

 Zone of D. Commune, 

 Saltwick near Whitby, 



Manchester Museum L. 8023. 



