FROM THE HASTINGS SAND. 



213 



for a completeness of ossification which existing Crocodiles do not 

 show. I have no doubt that the specimen was mature, on account 

 of the length of the neural spines (fig. 7, ns). All traces of sutures 

 are obliterated, and there is no trace of the inflation which, in living 

 Crocodiles, commonly marks the line of the neuro-central suture. 

 The articular ball of the centrum was as well ossified as in a lizard 

 or serpent (figs. 7, 8), and the ridges on the upper part of the neural 

 arch are defined with a sharpness unknown among living Crocodiles, 

 and suggestively Dinosaurian. The most distinctive features, how- 

 ever, of these vertebrae are, the side-to-side compression of the bodies 

 of the centrums, and the comparatively depressed neural arch, with 

 its strong zygapophysial ridges and well-developed neural spine. 

 The inferior ^-shaped approximation of the sides of the centrum, 

 which throws the neural arch out laterally above, is the principal 

 generic character seen in the dorsal region. The cervical vertebrae are 

 so imperfectly exposed that it is difficult to draw generic characters 

 from them ; but if the one specimen seen is rightly determined, it 

 shows a fundamental difference from procoelian Crocodiles in the ele- 

 vation of rhe facet for the rib upon the neural arch to a position which 

 almost adjoins the prezygapophysis. But as these vertebrae are not 

 continuous with the dorsal series, and there is no diapophysial 

 tubercle on the neural arch, I hesitate to draw what would other- 

 wise be a legitimate conclusion as to affinities from this character. 



Two or three cervical vertebrae are present, but only one is 

 partially free from the matrix. The second specimen shows the 

 outline of the neural arch from above ; but the neural spines, which 

 had the usual anterior position, are not preserved. The measurement 

 is 24 millim. from the prezygapophysis to the postzygapophysis, and 

 about 17 millim. from side to side over the zygapophysial facets, 

 while the least side-to-side measurement in the median constriction 

 is 8 millim. The one vertebra which is partly free, though badly 

 preserved, shows the neural arch to have been greatly depressed, so 

 that the height from the base of the centrum to the zygapophysis is 

 about 15 millim., and this is apparently also about the length of the 

 centrum. The left side of the centrum is subquadrate and concave, 

 with a small circular facet for the diapophysis external to and 

 impressed immediately below and behind the prezygapophysial facet. 

 There is no trace of a tubercle, such as is seen in Crocodiles ; though 

 the parapophysis has the usual oblong form, compressed from above 

 downward, and, though quite on the base of the side of the centrum, 

 is further distant from its anterior border than in existing Crocodiles. 

 The under surface of the centrum is too imperfectly preserved to 

 indicate whether a hypapophysis was developed : but the emargi- 

 nation of the undersides of the bases of the parapophysial tubercles 

 defines a constricted base to the centrum which is not seen in existing 

 Crocodiles. 



Seven dorsal vertebrae extend in continuous sequence, and their 

 centrums appear to increase slightly in length as they extend back- 

 ward. All are marked by the obliquity of the cup and ball, which 

 is rather more pronounced than in existing Crocodiles ; but as the 



