352 PALEONTOLOGY. 



longitudinal row, the middle one being very little larger than 

 the front and hind cone ; and these cones are not complicated 

 by any cingulnm or accessory basal cusp. The convex con- 

 dyle is below the level of the alveoli, 

 is pedunculate, and there is no angu- 

 lar process projecting beneath it. The 

 coronoid process is broad and high, 

 Jaw of Triconodon mordax with its hinder point not extended so 

 (nat. size), Purbeck. far back as the condyle; the depression 

 marking the insertion of the temporal muscle extends nearly 

 to the lower border of the jaw. There are the obscure remains 

 of three broken incisors, and the point of apparently a canine ; 

 next come the two stumps, or broken roots of a small pre- 

 molar ; then the crown of a second double-rooted premolar, 

 which shew a principal cone and a small anterior cusp ; the 

 next tooth is wanting ; then there is a large premolar, with 

 the two fangs raised some way out of their socket : the crown 

 of this tooth shews a principal cone, with a small anterior and 

 large posterior talon ; it rises, apparently from partial dis- 

 placement, higher than the succeeding molars ; these are three 

 in number, and present the characteristic three-coned structure 

 already described ; each cone is smooth, and convex exter- 

 nally. The three cones seem to answer to the three middle 

 or principal cones of the molars of Amjphilestes and Phascolo- 

 therium, but the front and hind cones are raised to near 

 equality with the middle cone in Triconodon. 



The lower jaw of this species, in the relation of the con- 

 dyle to the lower border, resembles that of Phascolotherium 

 more than that of Ampliitherinm, but it differs from both ; 

 there is not the same gradual curve from the condyle to the 

 symphysis as in Phascolotherium; and the condyle, besides 

 being on a lower level, is divided by a less deep notch from the 

 coronoid process. This process is larger in proportion to the 

 entire jaw ; approaches more nearly to the quadrate or rhom- 



