14 



OPTHALMOSAURUS PLEYDELLI. 



It will be seen 

 that the whole 

 bone is relatively 

 shorter than the 

 humerus of the 

 type specimen, 

 while the post- 

 axial facet in or- 

 der to receive the 

 pisiform is larger 

 and has a broad 

 and rounded ex- 

 tremity, the radial 

 and ulnar facets 

 are also shorter 

 and wider than 



in the type 

 species, the radial 

 terminating in a 

 blunt and round- 

 ed, instead of in 

 a pointed, ex- 

 tremity. These 

 features may 

 therefore be as- 

 sumed to be char- 

 acteristic of the 

 Kimmeridgian, 

 as distinct from 

 the Oxfordian 

 representative of 

 the genus. 



Fig. 3. Dorsal aspect and distal extremity of the Gillingham humerus. 



The two vertebrae sent me, which are believed to have been 

 associated with the humerus, belong to the transitional region 

 between the proper cervical and dorsal regions. 



Fig 4. Anterior left lateral aspect of a very late cervical vertebra of Ophthalmosaurus 

 pleydetti from the Kimmeridge clay of Gillingham, J nat. size, a upper, 6 lower costal 

 tubercle. 



The typical specimen has a length of 1'15, a height of 2 '25, and 

 a width of 2 - 8 inches across the posterior face. The two terminal 

 faces are distinctly cupped, the cupping of the anterior face being 



