nense_, as this reptile is termed,
are really to be regarded as of Triassic age. By Professor Huxley,
_Telerpeton_ is regarded as a Lizard, which cannot be considered
as "in any sense a less perfectly-organised creature than the
Gecko, whose swift and noiseless run over walls and ceilings
surprises the traveller in climates warmer than our own." The
"Elgin Sandstones" have also yielded another Lizard, which was
originally described by Professor Huxley under the name of
_Hyperodapedon_, the remains of the same genus having been
subsequently discovered in Triassic strata in India and South
Africa. The Lizards of this group must therefore have at one
time enjoyed a very wide distribution over the globe; and the
living _Sphenodon_ of New Zealand is believed by Professor Huxley
to be the nearest living ally of this family. The _Hyperodapedon_
of the Elgin Sandstones was about six feet in length, with limbs
adapted for terrestrial progression, but with the bodies of the
vertebrae slightly biconcave, and having two rows of palatal teeth,
which become worn down to the bone in old age. Lastly, the curious
_Rhynchosaurus_ of the Trias is also referred, by the eminent
comparative anatomist above mentioned, to the order of the Lizards.
In this singular reptile (fig. 151) the skull is somewhat bird-like,
and the jaws appear to have been destitute of teeth, and to have
been encased in a horny sheath like the beak of a Turtle or a
Bird. It is possible, however, that the palate was furnished
with teeth.

[Illustration: Fig. 151.--Skull of _Rhynchosaurus articeps_. Trias.
(After Owen.)]

The group of the Crocodiles and Alligators (_Crocadilia_),
distinguished by the fact that the teeth are implanted in distinct
sockets and the skin more or less extensively provided with bony
plates, is represented in the Triassic rocks by the _Stagonolepis_
of the Elgin Sandstones. The so-called "Thecodont" reptiles (such
as _Belodon, Thecodontosaurus_, and _Paloeosaurus_, fig. 152,
c, d, e) are also nearly related to the Crocodiles, though
it is doubtful if they should be absolutely referred to this
group. In these reptiles, the teeth are implanted in distinct
sockets in the jaws, their crowns being more or less compressed
and pointed, "with trenchant and finely serrate margins" (Owen).
The bodies of the vertebrae are hollowed out at both ends, but
the limbs appear to be adapted for progression on the land. The
genus _Belodon_ (fig. 152, c) is kno