THE TRIASSIC PERIOD. 219 
and Paleosaurus (fig. 153, ¢) has also been found in the Trias 
of the same region. ‘Teeth of the latter, however, are found, 
along with remains of Zhecodontosaurus (fig. 153, @), mn a 
singular magnesian conglomerate near Bristol, which was 
originally believed to be of Permian age, but which appears 
to be undoubtedly Triassic. 
RA RRA 
OANA: 
Fig. 152.—Triassic Reptiles. a, Skull of Mothosaurus mirabilis, reduced in size—Mus- 
chelkalk, Germany ; 4, Tooth of Simosaurus Gatllardoti, of the natural size—Muschel- 
kalk, Germany ; ¢, Tooth of Belodon Carolinensis—Trias, America; d, Tooth of Theco- 
dontosaurus antiguus, slightly enlarged—Britain ; ¢, Tooth of Palgosaurus platyodon, of 
the natural size—Britain. 
The Trias has also yielded the remains of the great marine 
reptiles which are often spoken of collectively as the ‘ Enalio- 
saurians ” or “ Sea-lizards,” and which will be more particularly 
spoken of in treating of the Jurassic period, of which they are 
more especially characteristic. In all these reptiles the limbs 
are flattened out, the digits being enclosed in a continuous 
skin, thus forming powerful swimming-paddles, resembling the 
“flippers” of the Whales and Dolphins both in their general 
structure and in function. The tail is also long, and adapted 
to act as a swimming-organ ; and there can be no doubt but 
that these extraordinary and often colossal reptiles frequented 
the sea, and only occasionally came to the land. The Triassic 
Enaliosaurs belong to a group of which the later genus 
Plesiosaurus is the type (the Sawropterygia). One of the best 
known of the Triassic genera is Wothosaurus (fig. 152, @), in 
which the neck was long and bird-like, the jaws being 1m- 
mensely elongated, and carrying numerous powerful conical 
teeth implanted in distinct sockets. ‘The teeth in Szmosaurus 
(152, 4) are of a similar nature ; but the orbits are of enormous 
size, indicating eyes of corresponding dimensions, and perhaps 
pointing to the nocturnal habits of the animal. In the singular 
