214 FAUNA ANTIQUA SIVALENSIS. 



entirely different in Lophiodon. In the Sewalik species the 

 middle bulge is the most salient, and most deeply notched at 

 the apex, where it forms an obtuse lobule. The two hollow 

 interspaces are strongly inclined inwards as they ascend and 

 terminate each in a three-sided pyramidal point, forming m 

 the vertical direction a double chevron or W outline, the re- 

 entering angles being at the apices of the bulges. In like 

 manner, from the inflexion of the pointed terminations of the 

 hollows and the projection of the bulges, the outer longitu- 

 dinal ridge of the crown follows a bold zig-zag direction, and 

 another -double chevi'on is formed in the horizontal plane of 

 the grinding surface. All this takes place in Chalicotheriiim, 

 exactly as in Palceotherium and Anoplotherium, but in a gi'eater 

 degree, the angular flexures being more marked. The an- 

 terior hollow space is considerably wider than the posterior, 

 which especially in the last molar slopes inwards towards the 

 back end of the tooth. Ch. Goldfussi, in these particulars, 

 agrees entirely vpith the Sewalik species, but besides the 

 lesser elevation of the crown the angular flexures of the 

 outer longitudinal ridge are still greater, so that their 

 apices occupy nearly the middle of the grinding surface. 



The anterior outer principal point, which forms in the 

 germ a distinct three-sided pyramid, wears down into a 

 crescentic disc of ivory. Its inner edge descends nearly 

 vertically towards the great central hollow, and is not 

 connected by means of a uniting ridge with the internal 

 large conical point which is opposed to it. A wide angular 

 gap intervenes between them. 



The posterior outer lobe forms a similar, but smaller, three- 

 sided low pyramid, the inner angle of which is connected 

 with a corresponding ridge from the posterior hiner ' hillock ' 

 opposed to it. A wide fissure having an antero-posterior 

 direction, and opening towards the posterior side of the 

 crown, intervenes. It is not as in Anoplotherium continuous 

 vpith the central longitudinal valley, but terminates at the 

 angle of junction of the posterior lobes, as in Palceotherium 

 and Rhinoceros, giving rise in advanced wear to an isolated 

 patch of enamel corresponding with the posterior annu- 

 lar ' fossette,' described by Cuvier in these genera. This fos- 

 sette is well shown by the third molar, which is much worn. 



The inner side of the crown is rounded at the angles, and 

 forms a nearly semicircular contour towards the palate. Like 

 the outer division, it is composed of two principal lobes or 

 ' hillocks.' The posterior of these forms a low three-sided 

 pyramid smaller than the corresponding outer lobe which is 

 opposed to it. It is separated from the great conical tubercle 

 which constitutes the anterior eminence by a wide gap formed 



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