324 RHINOCEROS. 



With the exception of two of the skulls, all the specimens 

 here enumerated are the products of Colonel Wood's zealous 

 and meritorious researches in the Grower Caves. On the 

 present occasion, I shall confine myself to the description of 

 such specimens only as are essential to establishing the spe- 

 cific distinctness of the form. 



Characters of the Molar Teeth. — The crowns of the upper 

 molar teeth in Rhinoceros present a common pattern of great 

 complexity, but subject to modifications in the different 

 species that are very constant, thus furnishing good cha- 

 racters for distinguishing them. Cuvier gave such a clear 

 and complete analysis of the elements that enter into the 

 composition of the crown, and was so happy and simple in 

 the terms by which he designated them, that little was left to 

 his successors besides the application of these terms to the 

 new forms discovered after his time. De Christol followed 

 up and extended the observations of Cuvier with much 

 ability, in his Essay on the European Eossil Species, and 

 succeeded more especially in tracing the peculiarities of cha- 

 racter produced by the attachment of the distal end of the 

 ' crochet ' to the contiguous parts, or by its remaining free. 

 The other points of principal importance to be regarded are 

 the number of fossettes on the worn triturating surface ; the 

 presence or absence of an internal basal bourrelet to the 

 three last premolars ; the form of the hind barrel of the last 

 true molar in respect of its being either simple and undivided, 

 as hi most of the species fossil or recent, or divided by a 

 posterior figure or fossette, which is so distinctive a cha- 

 racter of Rhinoceros simus, among the living, and of Rhinoceros 

 tichorhinus among the extinct forms ; and lastly, the relative 

 thickness of the coat of cement, a character the value of 

 which in the species of Rhinoceros has, in some measure, 

 been hitherto overlooked. 



Fig. 1 of PI. XVI. represents a fine fragment of the 

 upper jaw, right side, belonging to the collection of Colonel 

 Wood. It contains the five last molars in perfect preserva- 

 tion ; i.e. the penultimate and last premolars, with the three 

 true molars. The antepenultimate premolar (p.m. 2) has 

 been appended hi outline, from a reversed figure of the tooth 

 on the opposite side of the same individual. The age and 

 relative stage of wear in the different teeth are such as to 

 present the characters in the most favourable manner. The 

 antepenultimate true molar (m. 1) is so far advanced in 

 wear, that the posterior fossette is reduced to a small oval 

 pit; on the penultimate (m. 2) the detrition is so little 

 advanced, that the same valley is not yet isolated, and the 

 peculiar form of the ' crochet,' which constitutes one of the 



