136 



wards from the under part of each diapophysis, and a smaller process or tubercle projects 

 from the under part of each anterior zygapophysis. The other characters of the vertebra 

 conform to those in serpents generally. 



Huntcrian. 



643. Two anterior and two posterior abdominal vertebrae of a Rattlesnake (Crota- 



lus horridus). 



These show the long hypapophysis, which is hollow, as is shown hi the fractured speci- 

 men : but a single vertebra of the Crotalus might be distinguished from an anterior trunk- 

 vertebra of a Boa or Python by the following characters : the diapophysis developes a small, 

 circumscribed, articular tubercle from its upper convexity, and a short process from its under 

 part, extending downwards and forwards below the level of the centrum ; the anterior zyg- 

 apophysis seems to be supported by a similar process from the upper end of the diapophysis, 

 the point of which projects a little beyond the end of the zygapophysis ; the zygapophyses 

 are less produced outwards ; the zygantra are more distinct excavations. 



Hunterian. 



i 



Genus Naja. 



644. A considerable proportion of the separate bones of the skeleton of a Hooded 



Snake (Naja tripudians). 



The hypapophysis is continued, though of small size, from the posterior part of the lower 

 ridge of the vertebra throughout the abdominal region, as in the Viper. A minute process is 

 continued forwards from the under part of the diapophysis, the upper part of which is im- 

 pressed by a small pit anteriorly. 



In the portion of the skull preserved may be noticed the absence of the superorbital bones, 

 the broad and sloping superoccipital region separated by a strong arched transverse ridge 

 from the temporal fossa, and the two hypapophyses from the basioccipital, between which 

 the single hypapophysis of the basisphenoid is situated. 



Presented by Frederic D. Bennett, Esq., F.L.S. 



645. Four abdominal vertebrae and a pair of ribs of a Hooded Snake (Naja tripu- 



dians). 



The diapophysis presents the same well-marked tubercle upon its upper part, as in the 

 Rattlesnake, but its lower end is much less produced ; the bone underpropping the zygapo- 

 physis projects proportionally further beyond the articular surface : the neural spine is much 

 lower, and beyond the anterior third of the trunk the hypapophysis subsides into a ridge, 

 with its point produced backwards beneath the articular ball of the centrum ; the zygantra 

 are distinct cavities. 



Presented by Prof. Owen, F.R.S. 



