1843.] 239 



striking points in which it differs from the two latter terms of com- 

 parison, is in the dimensions of its back molar, which, with the 

 same amount of wear, is about half an inch higher than in A. com- 

 mune, and in this respect considerably exceeds even the longer and 

 wider tooth of the Chalicotherium. 



Length. Width. Height. 



A. Sivalense 1'3 1*5 1*1 



A. commune 1"2 ^•2 0'65 



Ch. Goldfussi 1-8 1-94 0-87 



On the whole, the Sewalik species appears to be most closely allied 

 to the Chalicotherium Goldfussi. The existence of a vacant diastema 

 in front of the anterior tooth would constitute a difference from the 

 Anoplotherian type of some importance. The characters generally 

 show a return from the ruminant tendencies of the Cuvierian species 

 back to a more pachydermatous type, and a closer affinity with the 

 rhinoceros, between which and A. commune it may ultimately prove 

 to be an intermediate form. Until the evidence for separation is 

 conclusive, the authors suggest leaving it with the genus Anoplo- 

 therium. The A. commune was determined by Cuvier to be of the 

 size of a small ass ; the A. Sivalense vfovXd. rank in dimensions be- 

 tween a horse and the small Sumatran Rhinoceros. 



Remarks on Chalicotherium. — Kaup appears to have founded this 

 genus, as distinct *from Anoplotherium, on real or supposed differ- 

 ences, 1st, in the rear molars ; 2nd, in the incisors ; 3rd, in the canine. 

 The difference in the rear molars consists in the size of the lobule of 

 the enamel into which the vertical bulges, near the apex, are notched ; 

 this character indicates, as he conceives, an affinity with the Tapir 

 and Lophiodon. But this lobule, even if constant, does not appear 

 to the authors of sufficient importance to constitute the basis of a 

 generic distinction. The general form of the rear molars of both 

 the upper and lower jaws is only an enlarged and less rectangular 

 representation of those of Anoplotherium. Moreover, in the direc- 

 tion of the ridges of the crown, and in the insulation of the conical 

 cusp, the accordance between Chalicotherium and Anoplotherium is 

 complete. As to the second distinction, drawn from the supposed 

 form of the incisors, the detached tooth which he figures and de- 

 scribes as a lower incisor (Oss. Foss. livraison ii. p. 30. pi. 7.), 

 judging from the figures and from a cast which the authors have 

 examined, very closely resembles, both in form and in the develop- 

 ment of the crown, the penultimate premolar of the A. Sivalense. 

 The channeled sides and the bifid extremity of the fang, indicating 

 two confluent fang roots, and the complicated form of the crown 

 with three mammilles on the inside, appear to the authors strongly to 

 militate against regarding the tooth as an incisor. They therefore 

 consider this tooth as an upper premolar (and probably as the penul- 

 timate one) of the right side. 



As to the third distinction, drawn from the canine teeth, judging 

 from a cast of the detached fragment which Kaup describes and 

 figures as the canine of Ch. Goldfussi, the authors consider that 

 determination as problematical. It seems to them to bear a resem- 



