152 FAUNA ANTIQUA SIVALENSIS. 



convex tlian those of the outer side, haAmig also a swell 

 vertically. The anterior one has the form of a cylinder 

 comi^ressed on the sides ; it is more worn than the hind one. 

 Its disc is transversely oblong, surrounded by a belt of 

 enamel, which at its outer anterior angle rtms into the 

 corresponding transverse crest (there is an accidental fissure 

 in the enamel here), so that in the continuation of the latter 

 it appears to double back on itself, descending in a sweep 

 upon the middle of the cylinder, where it temimates obtusely 

 at the upper third of it, forming a marked feature in the 

 tooth. 



The posterior division is more irregular in the outline of 

 its crown; the disc of detrition is less; the cincture of 

 enamel is wider and at its anterior outer angle projects in a 

 broad surface into the hoUow between the outer processes, 

 throwing out also a heel in the opposite direction into the 

 fossa between the inner divisions. Posteriorly it is notched 

 by an angular fissure into a sort of cordiform outline, with 

 the appearance of an additional pillar joined on to it opposite 

 the clefts of the spur. 



In the fossa of contraction between the divisions there 

 arises a considerable pillar of enamel, tuberculated laterally. 



The spur is a large convex bifid j)rocess, like two convex 

 cones in apposition, increased laterally by tubercles. The 

 apices formed by the cleft are circular and a little worn. 



The anterior or penultimate molar has the same general 

 form as the last one, but it is more simple, and its dimensions 

 are somewhat less. It is less deeply contracted in the mid- 

 dle, and the outline of the divisions of the shaft is less convex. 

 Its crown is much more worn. The anterior half is muti- 

 lated by a fractuie across, at a third of its length, and the 

 pair of processes have been worn down to one continuous 

 transverse disc. The posterior half has the divisions still 

 distinct. The outer hiUock resembles the adjoining one of 

 the last tooth; its disc is oblique, transversely oblong, and 

 encircled with an entire belt of enamel. The inner division 

 has none of the complexity of the corresponding portion of 

 the last tooth. It has a simple broadly-oblong outline and 

 disc. Its belt of enamel in the middle of the crown is 

 confused with the adjoining one of the anterior half. There 

 is no accessory pillar of enamel in the fossa between the 

 inner divisions, as in the last tooth. 



The middle transverse crest is seen in the furrow between 

 the outer hillocks, advancing but a short way forwards. 

 The posterior one is also present, its surface flattened by 

 wearuig. The mutilation of the tooth anteriorly leaves it 

 doubtful whether the anterior crest was present, or not, 



