Mr. T, Attliey on Anthracosauras Russelli. 159 



The teeth succeed each other as follows : tlie first is \ inch 

 behind the anterior termination of the ramus^the second 1\ inch 

 behind the first ; at the same distance from the second are the 

 third and fourth, which are in contact with each other ; half an 

 inch behind them are the fifth and sixth, also close together ; 

 and these are distant from the seventh -^'-g- inch ; from this to 

 the eighth is t\ "ich ; and there is the same distance between 

 the eighth and the two next (the ninth and tenth), which are 

 also close together ; these are ^q inch apart from the eleventh ; 

 the twelfth and thirteenth, likewise in contact, are at the same 

 distance behind the eleventh ; at y-jj inch further back are the 

 fourteenth, fifteenth, and sixteenth, at short distances from each 

 other 5 and at an interval of y^^ inch from the sixteenth are seen 

 the seventeenth, eighteenth, and nineteenth, which are in con- 

 tact and somewhat smaller than the others ; these are placed 

 near the posterior end of the dentary bone, terminating the 

 series. 



The outer surface of the left ramus of the mandible is given 

 in Plate X. fig. 2. This bears 15 teeth, nearly all of which 

 have been worked out on their inner surface and are therefore 

 not represented in the figure, their outer surface being covered 

 by the matrix as far as the margin of the alveolar border : por- 

 tions of six teeth are seen near to the symphysial end on this 

 side, and are irregularly placed. On the inner surface the 

 teeth are more uniformly disposed, and stand out nearly half an 

 inch above the alveolar border, which is very strong and 

 slightly concave from end to end of the ramus. The dentary 

 piece is united below to the angular, which forms the inferior 

 convex border of the ramus from the symphysis to its articu- 

 lation behind with the articular piece. This, from its union 

 with the angular, curves gently upwards, forming the posterior 

 border of the ramus, and is surmounted by the articular cavity ; 

 it sends out backwards no postarticular process. 



The coronoid process or rising is broad and elongated, pro- 

 jecting above the level both of the articular cavity and the 

 dentary bone ; a deep channel or mucus-groove runs along the 

 inferior margin of the ramus from the anterior to the posterior 

 end of the angular piece ; it then curves upwards and forwards 

 for a short space, and ends below the posterior margin of the 

 dentary bone. 



The teeth are arranged in a double series (maxillary and 

 palatal) on each side of the upper jaw, and in a single series 

 on each side of the lower jaw. They are of pretty uniform 

 size and shape throughout, excepting the palatal tusks. Those 

 of the mandible are anchylosed externally to the alveolar mar- 

 gin ; and a thin lamina of bone, running continuously over their 



