312 Mr. D. M. S. Watson o?i 



agrees exactly with it in size and in the state of wear of tlie 

 teeth ; it seems certainly to belong to the same individual 



(fig. 2). 



The jaw is remarkable for its thoroughly mammalian 

 character. The two rami are indistiiiguishably fused at the 

 symphysis, the upper surface of which is deeply grooved 

 ])Osteriorly. 



The number of incisors is not definitely shown, but there 

 appear to be three alveoli on each side. The only tooth 

 preserved is the 3rd left incisor, which is rather broken ; it 

 appears to have a simple, conical, rather blunt crown. 



The left canine is the better preserved; it is a powerful 

 tooth of oval section, showing on the outer side in the lower 

 unenamelled regicm a shallow groove. The anterior edge of 

 the tooth bears a low faintly crenulated ridge, the posterior 

 edge has a narrow worn face. 



lichiud the canine is a diastema of moderate length which 

 shows nothing remarkable, there being no trace of any worn- 

 down cheek-teeth such as Sceley described in " Diaste- 

 modon." On the left side 8 cheek-teeth are preserved, one 

 being solely represented by its alveolus. On this side the 

 teeth are very uniform in character, being all almost circular 

 cyliiulers with horizontally worn tops. Their worn summits 

 lie on a circle which is concave upwarils. 



On the right side the dentition is abnormal ; the first 

 tooth is low, its worn surface lying some 5 mm. below that 

 of the second, the second and third are simple cylinders 

 with a flat top, but the fourth has the posterior part of its 

 crown worn down obliquely. The fifth is a knob with a 

 rounded crown, and the sixth has a very dee[) groove on its 

 anterior edge. The seventh has a flat, much-worn crown 

 and is quite similar to the corresponding tooth of the 

 opposite side. 



The eighth tooth on the left side shows tljc very deep root 

 closed l)elow. 



No trace of any bone except the dcntary is to be seen in 

 this fragment of jaw. 



Description of some other Specitnens which add to our 

 knowledge of the Cynodunt Skull. 



Gomphognathus j,olyphayus, Seeley. 



Although Prof. Scclcy's description of the typo skull of 

 Gowphviiuaihus polyj'hagus is essentially complete and 



