Cope.] ^>" [Dec. 21, 



form of the neural spines, which are transverse to the long axis of the cen- 

 trum. That of one of the vertebrae is strongly emarginate so as to be bi- 

 furcate. The widely extended diaphophyses support the rib articulations, 

 and there are no capitular articular facets on the centra. 



The cervical vertebra is depressed, the anterior or convex extremity of 

 the centrum the most so. It is remarkable for its elongate form, exceeding 

 the proportions found in known Dinosauria and Crocodilia, and resembling 

 that seen in some fiuviatile tortoises. Near the anterior extremity a short, 

 robust parapophysis has its origin, from which it extends outwards and 

 downwards, and soon terminates in a truncate extremity which presents 

 downwards. A deep fossa occupies its upper base, and above this a deep 

 linear foramen extends throughoujt the greater part of the length of the 

 centrum. If this vertebra possesses a diapophysis it is rudimental. 



The caudal vertebras are amphiccelian, but not deeply so. They are sub- 

 quadrate in section, and not so short as the corresponding ones of Radro- 

 saurus. The most anterior one of the series has short, robust diapophyses, 

 and is more concave anteriorly than posteriorly. The other caudals are 

 more equally biconcave, but the cavity is very shallow on the most distal 

 of them. The centrum is relatively more elongate and compressed than 

 those of the others. None of them display the lateral pneumatic fossa 

 which exists in the dorsals, and where broken so as to permit a view of 

 the internal structure, the latter appears to consist of rather finely spongy 

 tissue. The chevron facets are not very well defined, and the neural spines 

 are of usual forms, and on two anterior vertebrae elongate. 



Many peculiarities are exhibited by the vertebrae of this species, which 

 are not described in saurians known up to the present time. Many of these 

 would have been lost in less careful hands than those of Mr. Lucas, and 

 science is much indebted to him for the preservation of many walls and 

 buttresses of light proportions. In general the external walls of the centra 

 are thin, and the processes are composed of laminae united by narrow mar- 

 gins. The vertebrae are lighter in proportion to their bulk than in any air- 

 breathing vertebrate. 



The anterior extremity of the centrum of the cervical vertebra is promi- 

 nently convex, and much depressed. The posterior and concave extremity 

 is wider, and of rather greater vertical diameter. The base of the neural 

 arch only occupies half of the length of the centrum, an equal extent of 

 the superior surface extending freely beyond it at its anterior and posterior 

 extremities. 



The linear lateral' foramen commences a little behind the anterior base of 

 the neural arch, and descending somewhat in its direction, terminates be- 

 neath the posterior extremity of the base of the neural arch. The base of 

 the latter overhangs the foramen and the base of the transverse process. 

 The interior surface of the centrum is concave, the concavity being bounded 

 in front by the inferior convex thickening of the extremity. Behind the 

 middle the surface becomes plane, and is, near the posterior extremity, 

 bounded on each side by a short angular ridge. 



