118 BRITISH FOSSIL REPTILES. 



more in thickness than in length ; in these changes it corresponds with the modern 

 Crocodiles ; it has been mutilated and worn in almost the same manner and degree as 

 the fourth cervical. 



The vertebra (figs. 1, 2, PI. 3) is a seventh cervical of a smaller individual of the 

 Crocodilm toUapicus. The hypapophysis has become more compressed and more 

 extended antero-posteriorly ; the parapophysis has become shortened antero-posteriorly, 

 and increased in vertical diameter. The anterior concave surface of the centrum 

 (fig. 1) is more circular, less extended transversely, than in the corresponding vertebra 

 of the recent Crocodiles compared with the fossil. 



Figures 3, 4, PI. 3, are two views of the eighth cervical of an individual of about 

 the same size as that to which the fourth and sixth cervicals in PL 3 A belong. Fig. 4, 

 exemplifies the same difi'erence which fig. 1 presents in regard to the more circular 

 contour of the anterior concave surface of the centrum as compared with recent 

 Crocodiles ; the bases of the neurapophyses are thicker and more rounded anteriorly ; 

 the neural canal is rather more contracted ; the base of the hypapophysis more extended 

 in the axis of the vertebra (see fig. 3) than in the recent Crocodiles compared. Tlie 

 parapophyses have now risen, as in those Crocodiles, to the suture of the neurapophysis, 

 and the diapophysis springs out at some distance above that suture. 



Fig. 6, PI. 3, shows the under surface of a dorsal vertebra, in which the 

 hypapophysis ceases to be developed (probably the fourth or fifth). 



Fig. 5, PI. 30, gives the same view of one of the lumbar vertebras, showing the 

 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. 



Figs. 5 and 6, PI. 3 A, give two views of the anterior sacral vertebra of the Crocodilus 

 toUapicus ; 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 jo ; 

 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, PI. 3, gives a side view of the characteristic, biconvex, anterior caudal 

 vertebra of the Crocodilus toUapicus. 



Figs. 8, 9, PL 3, 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 underjjropping buttress. 



