Ecliinodon. 
Table-case, 
Nuthetes 
24 Squamata. 
The following are of uncertain affinities, namely : — Ecliinodon , 
which was a large saurian probably of aquatic habits. The teeth 
were flat, broadly pointed, and the upper edges strongly serrated, 
hence the name “prickly-tootli.” A more formidable saurian 
C. 
Fig. 28.— (a) lateral, and (b) profile views of a tooth of Trachodon cantabrigiensis 
(Lydekker), Greensand, Cambridge; (o), tooth of Trachodon Foulki (Leidy), Upper 
Cretaceous ofNew Jersey, U.S.A. 
from the same deposit is the Nuthetes destructor. The teeth are 
flat, recurved, and finely serrated on their anterior and posterior 
margins, like miniature teeth of Megalosaurus , which they 
resemble. 
Order IV.— SQUAMATA (Scale-covered Reptiles). 
This order is largely represented by forms living at the 
present day, as it includes the true Lizards, the Chamaeleons, 
and the Serpents, and in the Cretaceous epoch by the great 
extinct Mosasaurians. . In this order the body may be either 
short, with well developed limbs and a distinct tail, as in the 
Lizards ; or it may be extremely elongated without any external 
trace of limbs, and passing gradually into the tail, as in the 
Snakes. As a rule, the whole body and limbs are covered with 
overlapping horny scales, and these may be underlain by an 
armour of bony dermal scutes. The limbs may be adapted for 
walking on land, or modified into paddles for swimming. In 
the skull the proximal end of the quadrate bone is more or less 
movably articulated ; the lower temporal arcade is wanting ; 
the post-orbital is generally fused with the post-frontal; the 
palate is more or less open, the pterygoids being nearly always 
separated by an interval from one another, and the premaxillce 
are frequently united. The vertebras are generally procoelous 
