26 Watson, Netv Genera of Upper Lmssic Plesiosaurs. 



it is probable that P. sueviais is a member of the group which 

 includes Microcleidiis and P. Gutlelmi Imperatoris. 



The vertebrae figured by Dames as the type of P. bavaricus, 

 appear to me to be not definitely referable to the same species. 



Fig. 1 is very like a cervical of my Sthe?iarosatirus Daickinsi, 

 but I do not believe that an isolated centrum of this type is really 

 identifiable ; there is, moreover, no indication in Dames' figure 

 of the ridge, connecting the anterior zygapophysis with the 

 posterior edge of the arch, which, in a cervical of Sthenarosaurus 

 of the same size, is quite conspicuous. 



The smaller and more perfect cervical represented in Fig. 2, 

 differs from the original of Fig. i, in that the ridge along the 

 haemal surface does not widen out posteriorly into a fiat surface, 



The arch represented in Fig. 2 differs from that of a similar 

 sized cervical of Sthenarosaurus, in having a larger neural spine, 

 much shorter posterior zygapophyses, and' in having the 

 zygapophysial table contracted before the postzygapophyses. 



These vertebrae, however, appear to belong to the group of 

 Plesiosaurs, which includes Sthenarosaurus. 



