74 



Dr. J. E. Gray on Spatulemys Lasalfc. 



in the ' Proc. Amer. Phil, Soc' for 18G9, p. 147 ; but it lias a 

 nuchal plate in the margin, and only live vertebral plates, and 

 is quite distinct from the genus Ilz/dromedusa. 



The mouth is semicircular in front, with the gape wide. 

 The palate is broad, flat, with the internal nostrils oval, rather 

 near together, rather before the hinder end of the alveolar 

 surface. Alveolar surfaces flat, broad, well separated from 

 one another in front, broadest about one third their length from 

 the front, and rather more than half the width behind, with a 

 rounded outline. Lower jaw with a slightly concave alveolar 

 surface, which is of the same breadth the whole of its 

 length, and has a well developed raised sharp edge on the 

 outer circumference and a less developed one on the inner 

 margin. There is a well-marked conical tooth-like promi- 

 nence in the front of the middle of the outer edge. 



The upper and lower jaws of 

 Sptduh'tiii/s Lasahe. 



The upper and lower jaws of 

 Jli/draspis 7'amc('2)s. 



The alveolar surface, as seen in the stuffed specimen, is very 

 like that of the skeleton of Hi/drasjns raniceps : but the alveo- 

 lar plates of the upper jaw of the latter species are well 

 separated in the middle, and the internal nostrils are much 

 further back in the palate ; and the alveolar edge of the lower 

 jaw is even — and not with the rounded tubercle on each side, 

 rather behind the central tube. 



In Hydrasiyis Gordonii (P. Z. S. 1868, p. 503) the alveo- 

 lar plates of each side of the upper jaw are separated by a 

 narrow linear space ; they are moderately wide and nearly the 

 same width for the whole length, truncated at the front end, 

 and gradually rounded off at the hinder end. The internal 



