14 FOSSIL REPTILIA OF THE LONDON CLAY. 



Crocodilus Hastingsije. 



Vertebra referable to the Crocodilus Hastings^, Tab. IX. 



The fossil crocodilian vertebrae obtained from the Eocene sand at Hordle, notwith- 

 standing the comparatively limited extent of the researches in that interesting 

 formation, are at least as abundant as those which have been discovered at Sheppy, 

 but they do not, as at that locality, indicate two distinct species ; all that have, hitherto, 

 been found belong to one and the same kind of Crocodile, and from their robust 

 proportions, would seem to have come from a species with a short and broad muzzle, 

 like that of the Crocodile or Alligator, the fossil skulls of which have been described. 



Perhaps the most perfect fossil reptilian vertebra that has hitherto been discovered 

 is the one figured, of the natural size, in T. IX, fig. 1, 2, and 3. It is the fifth 

 cervical vertebra. As compared with that of the Crocodilus toliapicus (T. V, fig. 

 1, 2), which it resembles in size, the lrypapophysis, Jig (fig. 2, T. IX), is much more 

 compressed, and the under part of the centrum is more extensively and deeply exca- 

 vated between it and the parapophyses (p) ; it is also excavated on each side behind 

 the base of the hypapophysis, from which a pi-ogressively widening smooth ridge is 

 continued to near the posterior surface of the centrum. The interspace at the side of 

 the vertebra, between the parapophysis and diapophysis, is smaller but deeper in the 

 Crocodilus Hastingsice. The neurapophyses meet above the centrum in both ; but in the 

 Crocodilus Hastingsice they are thicker anteriorly and thinner at their posterior border, 

 and the neural canal (fig. 2, n) is more contracted than in the Crocodilus toliapicus. 



As compared with the cervical vertebra of the Crocodilus champsoides from Sheppy, 

 the present vertebra differs in the form of the hypapophysis in a greater degree than from 

 the Crocodilus toliapicus. Fig. 8, T. V, shows as little as does fig. 2 in the same plate, 

 the median ridge and lateral excavations of the under part of the centrum which charac- 

 terise the present vertebra of the Crocodilus Hastingsice. The Crocodilus champsoides 

 resembles the Crocodilus Hastingsice in the character of the proportion and depression 

 of that part of the side of the centrum forming the interspace between the par- 

 apophj r sis and diapophysis ; but the antero-posterior extent of the parapophysis is 

 relatively less in that Sheppjr species. The outer surfaces of the neurapophyses in the 

 Crocodilus Hastingsice slope or converge towards each other from before backwards, in 

 a much greater degree than in either of the Sheppy species. I have not observed in 

 any recent Crocodile or Alligator the median ridge, continued backwards from the 

 hypapophysis and the lateral depressions, so strongly developed, as in the Crocodilus 

 Hastingsice. The fore part of the neurapophyses is relatively thicker in this than in the 

 recent species. The pleurapophyses pi, (figs. 1 , 2), are well developed both forwards and 

 backwards, and. the latter productions are expanded and excavated above for the reception 

 of the fore part of the succeeding cervical rib. The zygapophyses (z) are thicker at their 



