«e?o Genus n/' Rliinocerotidse. 



715 



ramus just beyond the level of the mental foramen at a point 

 where there is a slight concavity in the type (fio-. 2). The 

 diameter of the roots of the incisors is rather larger than in 

 those of the type, and it is possible that this fragment 

 belongs to a larger male of the same species — at any rate, it 

 is best to refer it here until further material proves the 

 contrary. 



From the same locality come certain vertebrae and foot- 

 bones which are provisionally referred to this species. 

 Among them is chiefly noticeable an atlas (fig. 3) of extra- 

 ordinary size, far too large for the specimen described above, 



Fio-. 3. 



Atlas, upper surface. 



but possibly belonging to a very large male, since the type is 

 supposed to be a female. The measurements of this bone 

 are as follows, and the measurements of an atlas of R. hicornis 

 are given for comparison : — 



P. hifftiense. H. hicomis. 

 cm. cm. 



Extreme width from wing to wing .... 47-5 28-5 



Depth of wing 24-0 1 l-O 



Extreme width of condylar surface .... 27*4 137 



The edges of the wings are much roughened for the attach- 

 ment of muscles. The vertebrarterial canal is similar to that 



