RHINOCEROS TICHORHINUS. 341 



Rhinoceros of nearly the same age as that from Lawford ; 

 the summit of the second crescent of the fourth premolar 

 shows that it had just come into use at the period when 

 the animal perished. The anterior of the three ridges, on 

 the inner side of the crown of the third and fourth pre- 

 molars, supports a small oblong tubercle,* a variety not 

 present in the Lawford specimen. In the Rhinoceros lepto- 

 rhinus of the fresh-water deposits in Lombardy, a species 

 also co-existing of old with the tichorhine Rhinoceros in 

 Britain, the premolar teeth extend forwards much closer 

 to the anterior end of the jaw, and the second premolar 

 is placed in advance of the posterior border of the sym- 

 physis (see figs. 132 and 134). 



The portion of lower jaw, with two molar teeth, 

 which forms the subject of the first plate in Douglas's ' Dis- 

 sertation,' and the foundation of much ingenious reason- 

 ing, on the supposition that it was part of a Hippopotamus, 

 belongs to a Rhinoceros, and probably to the extinct 

 tichorhine species. It was discovered in "a stratum of 

 drift or river sand, blended with a kind of clay, of a 

 yellowish grey tinge," at the depth of twelve feet, in dig- 



* Cuvier, in detailing the discovery at Avary of certain fossils, which he refers 

 to the Rhinoceros incisions, says, " Enfin une dent inferieure, plus usee, est peut- 

 etre la cinquieme ou la sixieme ; j'y vois, au deuxieme croissant du cote interne, 

 un crochet que je ne retrouve pas dans les autres especes." ' Ossemens Fossiles,' 

 1822, torn. iii. p. 391. M. Christol, believing that he had discovered this 

 character in the molars of the lower jaw of the Rhinoceros tichorhinus, regards 

 it as distinctive of that species. 'Annales des Sciences,' 1835, torn. iv. p. 62. 

 In the lower molar tooth, which he figures to illustrate this character, it is 

 shown as a minute notch near the upper and posterior part of the middle ridge 

 on the inner side of the crown, which ridge is formed by the posterior and 

 inner termination of the first or anterior crescent ; the notch cuts that ridge in 

 a direction downwards and forwards, detaching from it a small conical process. 

 I cannot find a trace of this character in any of the lower molars of the 

 Rhinoceros tichorhinus which I have examined ; and I have especially compared 

 with the figure given by M. Christol, loc. cit., pi. iii. fig. 1 , a molar, the fourth, 

 of the same size and with the same degree of usage. Such small tubercle, 

 notch, or crochet, wherever developed, is most probably an accidental variety. 



