154 



MARINE REPTILES OE THE OXFORD CLAY. 



whether this is formed by a median parasphenoid element or by the elevation of the 

 pterygoids along a median line of symphysis. Mr. Leeds points out that Deslong- 

 ehamps figures a similar ridge in Pelagosaurvs, but it does not seem to be present in 

 Steneosaurvs. At its hinder end the vomer (parasphenoidj is concealed ventrally 



Sections across the nasal canals of MeiriorJtynclitis hrachyrhynchus at the various levels marked 1-4 on text- 

 fig. 58. The vomer (parasphenoid) is left blank, the palatines are shaded, and the pteiygoids are shown 

 in black. (E. 3700, nat. size.; (After E. Tlmrlow Leeds, Quart. Journ. Geol. Soc. vol. hiv. (190S) 

 r . 354, fig. 2.) 



by the overlap of the pterygoids meeting in the middle line (text-fig. 58), while 

 dorsally it seems to have fused with the lower face of the basisphenoid, which 



