4 GUIDE TO THE FOSSIL REPTILES, AMPHIBIANS, FISHES. 
Table-case 
F. 
I 
Wall-case 
1 . 
rather slender neck, and lizard-like limbs—the other with a 
large head, short and stout neck, and well-formed paddles. 
The first, kind is represented by small reptiles, which are 
named Dolichosauria (“ long lizards ”) in allusion to their 
elongated shape. The backbone is indeed snake-like, and 
the vertebrae when found isolated have sometimes been 
mistaken for those of snakes. Dolichosaurus itself is repre¬ 
sented in Table-case F by a fine specimen from the Chalk of 
Biirham, Kent. There is also a nearly complete skeleton 
of a closely related animal, in hard limestone of the same 
geological age, from Lesina, Dalmatia. 
Sub-order 4.—Mosasauria. 
The second group of Cretaceous swimming reptiles just 
mentioned comprises large animals, shaped more or less like 
elongated porpoises or ichthyosaurs. Their skull resembles 
that of a lizard, but the jaws are as loose as those of snakes 
Fig. 1.—Jaws of Mosasaurus camperi, from the Upper Chalk of Maastricht, 
^Holland ; about one-fifteenth nat. size. (Wall-case 1.) 
for swallowing bulky prey, while some of the palate-bones 
bear recurved teeth. The teeth themselves are large and 
conical, and firmly fixed by swollen bases to the supporting- 
jaws (Fig. 1). The eye is surrounded by a ring of “ sclerotic 
plates.” The vertebrae are united by shallow ball-and-socket 
joints, the ball being posterior. Both pairs of limbs and their 
supports are fundamentally like those of a lizard, but modified 
into effective paddles (Fig. 2). The toes are flattened from 
