CROCODILIA. 129 



hypapophysis, that of the third cervical vertebra of the Alhgator, but with an indication 

 of a median rising and lateral depressions, behind that process, Uke those which are 

 more decisively shown in the fifth cervical vertebra of the larger individual of the Croco- 

 dilus HastingsicB, to which species I believe the specimen fig. 4 to belong. It is the 

 homologous vertebra with fig. 8, PI. 3 A, and well illustrates the different proportions 

 of the bones in different species of Crocodile. 



Fig. 6 gives a view of the anterior surface of the first sacral vertebra of the 

 Crocodilus Ilastingsia : the under surface of the centrum has ceased to develope the 

 median ridge ; the short and thick ribs {-pi) have completely coalesced with both the 

 centrum and neural arch. The anterior concavity has a fuller and more exact elliptical 

 form than that of the Crocodilus toliapicus (fig. 5, PI. 3 A) ; the anterior zygapophyses 

 do not project over the rim of that concavity ; but, like those of the Alligator and 

 Crocodile, they are more transversely extended than in the Gavial. 



The general proportions of the first caudal vertebra (fig. 7, PI. 1 D) are intermediate 

 between those of the Crocodilus toliapicus (fig. 7, PI. 3) and of the Crocodilus champsoides 

 (fig. 10, PI. 2>A) : the under surface of the centrum is flat, not concave, lengthwise, as 

 in both the Sheppy Crocodiles ; the side of the centrum is irregularly tuberculate, not 

 smooth, and concave lengthwise; the broad and high neural spine is deeply grooved at its 

 fore part : a smaller proportion of the hinder end of the centrum (fig. 5) is occupied by 

 the articular ball than we find in the antecedent vertebrae. 



As none of the other numerous vertebrae and portions of vertebrae give any indi- 

 cations of a different species from the Crocodilus Hastingsice, or add any material 

 characters to those of that species which have been deduced from the parts of the 

 skeleton already described, I refrain from trespassing on the reader's attention or 

 occupying further space by their description or figures. 



Genus — Gavialis, Oppel. 



Gavialis Dixoni, Oiven. Plate 3 B. 



The characters of the genus Gavialis are much more strongly marked than are those 

 which distinguish the Alligators from the Crocodiles, and leave no ambiguity in the 

 conclusions that may be deduced from them. The present interesting addition to the 

 catalogue of British Fossil Reptiles, is due to the discovery in the Eocene deposits at 

 Bracklesham, by my lamented friend the late Frederic Dixon, Esq., F.G.S., of the remains 

 figured in PI. 3 B. The portions of the lower jaw demonstrate, by the slender pro- 

 portions of the mandibular rami (figs. 1, 5), the extent of the symphysis, the uniform 

 level of the alveolar series, and the nearly equal distance of the sockets of the com- 

 paratively small, slender, and equal-sized teeth, the former existence in England, 

 during the early tertiary periods, of a Crocodilian with the maxillary and dental 



