46 
Sauropterygia 
Wall-cases, 
Nos. 9, 10, 
13. 
Table-cases, 
Nos. 15, 16, 
17. 
Z- 
lio. Cl.— Anterior and left lateral aspects of a cervical vertebra of Cimoliosauru s 
Jiichardsoni (Lydekker) from the Oxford Clay, Weymouth, Dorset. -J- nat. size, 
co, rib ; prz, prezygapophysis; ptz, postzygapophysis. 
caudal vertebrae carry true ribs and also clievron bones. In 
the pectoral girdle, the coracoids unite in a ventral symphysis, 
and the scapulae may also meet on the median line. The limbs 
Fxo. 62— Ventral aspect of the pectoral girdle of Plesiosaurus Ilawkinsii (Owen), from 
the Lower Lias, Street, Somerset (about \ nat. size), osl, omosternum ; sc, scapula ; 
pcor, ventral (precoracoidal) plate of scapula; gl, glenoid cavity; cor, coracoid. 
(In reality the omosternum is wedged in between the extremities of the coracoids.) 
vary, being in some genera adapted for progression on land, in 
others converted into paddles suited for an aquatic existence. 
The humerus and femur are always of considerable length, the 
phalangeal bones are elongated, but no additional digits are 
developed. In habits the members of this order were carnivo- 
rous, and either marine or terrestrial. 
