Dr. C. W. Andreivs — Extinct Egyptian Vertebrates. 439 



from the Eocene (Lower and Middle) of Sheppey and Bracklesliam, 

 and it is very interesting to find a similar form occurring in the 

 Lower Tertiary deposits of Egypt. Some shells which occur asso- 

 ciated with these remains have lately been described by Cossmann ^ 

 from almost the same locality ; they are referred by bim to the 

 Middle Eocene (Nummulitic), so probably it may turn out that 

 the beds in which Moeritherium, Bradytherium, and the reptiles 

 described in this paper are found, are somewhat older than stated 

 in Part I, and are in fact Middle Eocene. This question will no 

 doubt be settled by Mr. Beadnell in the section relating to the 

 stratigraphy of the district. 



^J/^-^ 



hijfi hyp. 



Fig. 2. — Vertebra of Ifosriophis. Two-thirds natural size. (A) From side ; 

 (B) from front, a.z. anterior zygapophysis ; /iy^j;. hypapophysis ; «. process 

 on back of neural arch ; n.s. neural spine ; p.z. posterior zygapophysis ; 

 r. facet for rib ; zyg.s. zygosphene. 



The chief characteristic of these vertebrae is the great height of 

 the neural spine (Fig. 2, n.s.), and with this seems to be correlated 

 the relative narrowness of the centrum in proportion to its length 

 and the ventral and downwardly directed position of the transverse 

 processes (r.). All these characters occur to a less degree in 

 Palceopliis. Another point of similarity is the presence on either 

 side of the posterior part of the neural arch of a large backwardly 

 and upwardly projecting process (Fig. 2, n.), from the tip of which 

 a ridge runs downward and forward to the base of the anterior 

 zygapophysis. This process is more developed here than in 

 Palceophis, to which, according to Owen, it is almost peculiar, 

 only a trace being found in other Ophidian vertebra. 



The transverse processes project downward below the level of 

 the centrum, and their lower ends may even be slightly bent in 



' Cossmann : "Additions u la Faune Nummulitique d'Egypte" (Institut Egyptian, 

 Cairo, 1901). 



