84 SCIENTIFIC AND LITERARY NOTES. 
rus, Acolodon, Suchosaurus, Goniopholis, Pcecilopleuron, Stagonolepis, (?) &c.* 
Species of the above genera range from the lias to the chalk inclusive. 
Sub-Order Opisthocelia (om@os, behind, korAos, hollow: vertebre concave 
behind, convex in front).—The small group of Crocodilia, so-called, is an artificial 
one based upon more or less of the anterior trunk vertebre being united by ball 
and-socket joints, but having the ball in front, instead of, as in modern crocodiles, 
behind. Cuvier first pointed out this peculiarity} in a crocodilian from the 
Oxfordian beds at Harfleur and the Kimmeridgian at Havre. Prof. Owen had 
described similar Opisthoccelian vertebrae from the Great Oolite at Chipping Nor- 
ton, from the Upper Lias of Whitby, and, but of much larger size, from the Weal- 
den formations of Sussex and the Isle of Wight. These specimens probably 
belonged, as suggested by him in 1841,{ to the fore part of the same vertebral 
column as the vertebra, flat at the fore part, and slightly hollow behind, on which 
he founded the genus Cetiosaurus. The smaller Opisthoccelian vertebree described 
by Cuvier have been referred by Von Meyer to a genus called Streptospondylus. 
In one species from the Wealden, dorsal vertebra, measuring eight inches across, 
are only four inches in length, and caudal vertebrae nearly seven inches across are 
less than four inches in length. These characterize the species called Cetiosaurus 
brevis. Caudal vertebre, measuring seven inches deep and five and a half inches 
in length, from the Lower Oolite at Chipping Norton, and the Great Oolite at 
Enstone, represent the species called Cetiosawrus medius. Caudal vertebre from 
the Portland Stone at Garsington, Oxfordshire, measuring seven inches nine lines 
across and seven inches in length, were referred by the author to the Cetzosawrus 
longus. The latter, he remarked, must have been the most gigantic of crocodilians. 
Sub-Order Prelia (xpos, front, xoiros, hollow: vertebrae with the cup at the 
fore part and the ball behind). Crocodilians with cup-and-ball vertebre, like those 
of living species, first make their appearance in the greensand of N. America 
(Croc. basifissus and C. basttruncatus, Ow.)|| In Europe their remains are first 
found in the tertiary strata. Such remains from the plastic clay of Meudon have 
been referred to Crocodilus isorhynchus, C. celorhyncus, C. Becquereli. In the 
‘ Caleaire Grossier’ of Argenton and Castelnaudry have been found the C. Rallin- 
ati, and C. Dodanii. In the coeval eocene London clay, at Sheppy Island, the 
entire skull and characteristic parts of the skeleton of C. toliapicus and C. champ- 
soides occur. In the somewhat later eocene beds at Bracklesham occur the remains 
of the Gavial-like C. Dixoni. In the Hordle beds have been found the C. 
* This was referred to the present order by the author, after inspection of the specimens 
brought to the British Association Meeting, at Leeds, by Sir R. Murchison, but with a note 
on the greater relative breadth of the coracoid, as shown by the part of the bone then 
exposed.—(Encyclo. Brit. Art. ‘Palzeontology’). Prof. Huxley, to whom the specimens were 
subsequently consigned for description, together with others directly transmitted to him, 
confirms the general crocodilian character of Stagonolepis. I regard the modifications of 
the limb-bones as indications of affinity with the Thecodontia; but the structure of the 
cranium must be ascertained to determine this point. The associated fossils, especially those 
allied to Rynchosaurus, in the Elgin sandstones, have a triassic character. 
+ ‘Annales du Muséum,’ tom. xii, p. 83, pl. x. xi. 
+‘ Report on British Fossil Reptiles,” Trans. British Association, for 1841, p. 96. 
Quarterly Journal of the Geological Society. 
