CRETACEOUS REPTILES. 387 
satisfactorily established by the discovery of portions of jaws and teeth associated 
with such vertebrae. The first of these specimens, which discloses a small ex- 
tinct Lacertian, distinct from Raphiosaurus, and characteristic of the chalk 
formation, was obtained from the lower chalk at Clayton, Sussex, and forms part 
of the choice and instructive collection of Henry Catt, Esq., of Brighton. It is 
figured in Pl. XXXVIL. figs. 19 & 20, and a group of vertebre of apparently the 
same species is represented in fig. 18. 
These vertebrze are represented of the natural size. Like those first figured 
in the ‘ Geological Transactions,’ tom. cit., pl. 39, they present an anterior con- 
cavity or cup, and a posterior ball upon the bodies for their reciprocal articula- 
tion ; and a tubercle is developed from each side of the vertebral body near its 
anterior end for the articulation of the rib. The non-articular surface of the 
vertebra is smooth ; its under part is concave in the axis of the body, convex 
transversely. On the very probable supposition, however, that the vertebre, v, 
fig. 19, belonged to the same animal as the jaw which is imbedded in the same 
portion of chalk, such vertebrae must be smaller in proportion to the head than 
in the extinct species of lacertine Saurian, likewise from the chalk (Pl. XX XVIII. 
fig. 1), and to which there will be adduced reasons for believing that the fine 
specimen in the collection of Sir P. de M. Grey Egerton, Bart. (Pl. XX XIX. fig. 4) 
belongs. The fossil jaw and teeth in Pl. XX XVII. fig. 19. determine the distinct- 
ness of the Coniasaurus from the above-named fossil as well as from all known 
recent Lizards. 
The dentary bone contains from 18 to 20 teeth ; the anterior five or six teeth 
are slender, slightly recurved, pointed or laniariform ; the rest progressively in- 
crease in thickness as they are placed further back ; expanding above the neck, 
slightly compressed laterally, most convex inwardly, with an anterior border 
which is more prominent and curved than the posterior one: the anterior margin 
is further characterized by a longitudinal groove on its outer side. Some of the 
posterior teeth show a slight longitudinal indent near the posterior obtuse border ; 
on the last molar is smaller and more obtuse than the others. The enamel is very 
finely wrinkled. The teeth are closely and rather obliquely arranged ; the long 
simple roots are anchylosed to the bottom of the shallow alveolar groove and to 
the inner side of the outer wall, and their excavations indicate the usual mode of 
succession and displacement : a few alternate teeth have been shed. 
The mode of attachment more resembles that which characterises the teeth in 
Lacerta proper and other Celodont genera of the Lacertian tribe; but in the 
