Lariosauridce. 
51 
species. Only a few complete examples of some of these genera Notho- 
are known, the rest being mostly based upon more or less sauras - 
fragmentary remains. These old marine lizards were most Table-case, 
abundant in Mesozoic times, particularly at the period of the No ‘ 17 ' 
deposition of the Lias, Kimmeridge and Oxford Clays ; the 
latest-known genus, Polyptycliodon, being found in the Chalk. 
Fig. 69. — Palatal aspect of the cranium of Nothosaurus mirabilis (Munster), Muschelkalk, 
Germany (? nat. size), pmx, premaxilla; nar, posterior nares ; vo, vomer; mx, 
maxilla; pal , palatine; pt, pterygoid; a, ala of same; 6, quadratic ridge; qu, quad- 
rate bone ; oc, occipital condyle. The posterior extremity of the palatine was pro- 
bably formed by a transverse bone, but the suture is not visible. (Table-case, No. 1 7.) 
Most of the “ Sea-Dragons,” both the long and the short- 
necked forms, were obtained from the Lias of Street, Somerset- 
shire, Lyme Regis, Dorsetshire, Barrow-on-Soar, Leicestershire, 
and Whitby in Yorkshire ; or from the Oxford Clay of Peter- 
borough and Weymouth, and the Kimmeridge Clay of Dorset- 
shire ; in fact, their geological and geographical distribution 
seem to have been almost identical. 
Fig. 70. — Right lateral aspect of the skull of Nothosaurus mirabilis (Munster), reduced; 
from the Muschelkalk of Germany. 
The Lariosaurid.®, represented by the Italian Lafiosaurus Wall-case, 
and the German genus Neusticosaurus , appear to connect the No ‘ ^ * 
marine Plesiosauridj: with the freshwater and terrestrial 
Nothosauridj:. The skull was short, the neck relatively long ; 
the humerus short, the femur elongated, and the terminal 
phalangeals were furnished with claws. 
