218 



A. GtJNTHEE ON SOME EAEE REPTILES 



fifth, and sixth the posterior zygapophyses coalesce, forming a prominent process with 

 a button-like end, the articular facets being at the under surface, and separated 

 from each other by a narrow groove. In the seventh vertebra these zygapophyses are 

 enormously developed into a short high club-shaped process, with the articular sur- 



Fig. 2. 



Sixth, seventh, and eighth ceryical vertcbroe of CheJi/sfuiibnala (lower and lateral views). 



faces coalesced into one, and at the lower surface of the bone. The eighth vertebra is 

 distinguished by an extremely compressed centrum, much longer than the short neural 

 arch, by cylindrical pleurapophyses, and by a long coalesced posterior zygapophysis, 

 which is also club-shaped, but much less thick than that of the seventh vertebra. A 

 division into two halves is indicated by a shallow notch at the top, and a deep hollow 

 between the articular facets, which are placed at the sides and not on the lower surface 

 of the process ; a deep groove is hollowed out in front of each articular facet. 



In connexion with this peculiar structure of the posterior cervical vertebrae it should 

 be remembered that Chelys, like Clielodina, does not retract neck and head backwards 

 within the shell in the median line of the body, but bends it sideways, so that the head 

 lies either on the right or left forearm. 



The number of dorsal vertebrae is eleven, the three hindmost forming a sacrum. 



Caudal vertebrae 17 or 19. 



Metopoceros coenutus (Wagl.). (Plates XLIII. and XLIV.) 

 For many years the single specimen of this Lizard in the Paris Museum, described 

 by Lacepede and Dumeril, remained unique, until a living example was presented to 

 the Society in the year 1871' ; and, singularly, ever since that period the Eeptile-House 



' Proc. Zool. Soc. 1871, p. 627. 



