CROCODILIA. 35 



elongation of the centrum, and the broad bases of the depressed diapophyses ; there is an 

 indication of two longitudinal risings towards the back part of the under surface of the 

 centrum. 



Fig. 5 and 6, T. V, give two views of the anterior sacral vertebra of the Crocodilm 

 toliapicus ; it is concave and much expanded transversely at its fore part (fig. 5), 

 flattened and contracted behind. Traces of the suture remain to show the proportion 

 of the anterior articular surface which is formed by the base of the pleurapophysis p ; 

 and fig. 6 shows the extension of that base from the side of the centrum upon the 

 diapophysis or overhanging base of the neurapophysis ; the under surface of the 

 centrum of this vertebra has a slight median longitudinal rising. 



Fig. 7, T. IV, gives a side view of the characteristic, biconvex, anterior caudal 

 vertebra of the Crocodilus toliapicus. 



Fig. 8, 9, T. IV, give two views of a middle caudal vertebra : in fig. 9 are shown 

 the characteristic hypapophysial ridges extending from the articular surfaces for the 

 hsemapophyses at the hind part of that aspect of the centrum : in fig. 8 the processes 

 of the neural arch are restored in outline ; a thick and low ridge extends from the 

 middle of the side of the centrum to the base of the transverse process which it 

 strengthens, like an underpropping buttress. 



Vertebra of the Crocodilus champsoides. 



Fig. 7 and 8, T. V, give two views of the third cervical vertebra of the above- 

 named gavial-like Crocodile, which vertebra, besides its longer and more slender propor- 

 tions, differs in the smaller size of its hypapophysis from the corresponding vertebra in 

 any existing species of Crocodile or Gavial : the process in question being in the form of 

 a low crescentic ridge, as shown at figure 8, between the bases of the parapophyses (p). 



Both parapophyses terminate by a convex surface, which appears to have been 

 a natural one. Between the parapophysis (p) and diapophysis (d), fig. 7, the side of the 

 centrum is more deeply excavated than in the Crocodilus toliapicus. The centrum 

 contributes a small part to the base of the diapophysis, as in the third cervical vertebra 

 of modern Crocodiles. The neurapophysis are thinner than in the Croc, toliapicus, and 

 their bases do not join one another above the centrum. The longitudinal ridge 

 extending from the anterior to the posterior zygapophysis is sharply defined. 



Fig. 4, T. V, is the first dorsal vertebra of the Crocodilus champsoides, in which, as 

 in existing Crocodiles, the parapophysis (p) has passed almost wholly from the centrum 

 upon the neurapophysis, the diapophysis (d) having been subject to a corresponding 

 ascent. The base of the compressed hypapophysis extends over the anterior third of 

 the middle line of the under surface of the centrum. There is a remarkable transverse 

 constriction at the base of the posterior ball of the centrum, as if a string had been tied 

 round that part when it was soft, and there is no appearance of this groove having been 

 produced by any erosion of the fossil, or being otherwise than natural. 



