EHINOCEEOS HEMITCECHUS. 



325 



distinctive marks of the species, is well shown; while the 

 apex of the crown of the last molar had only come slightly 

 into use. The premolars are well worn, and in the normal 

 ratio, to the state of the antepenultimate true molar (m. 1). 

 All the teeth are invested by a very thick coat of cement, 

 which is denuded from the upper part of the anterior barrel 

 of the last molar (m. 3). The specimen was yielded by the 

 last excavations in ' Minchin Hole.' 



Fig. 2 of PL XVI. represents another fine fragment in 

 Colonel Wood's collection, composing the four last molars, 

 also of the left side of the upper jaw, but considerably more 

 worn, the crowns of the last premolar (p.m. 4) and of the 

 antepenultimate true molar (m. 1) being ground down to a 

 uniform surface, each enclosing two fossettes ; while the last 

 true molar (m. 3) shows the various folds of enamel, and the 

 form of the ' crochet' in the stage of abrasion best suited for 

 exhibiting the characters. All the teeth in this specimen 

 also are enveloped by a thick coat of cement. It was yielded 

 by ' Minchin Hole.' 



Pigs. 1 and 2 of PL XYII. represent a fragment of the right 

 side of the upper jaw, containing three consecutive teeth, 

 namely, the last premolar mutilated at the outer surface, and 

 the antepenultimate and penultimate true molars, the latter 

 having the inner side of the posterior barrel fractured. The 

 crowns are in a less advanced stage of wear than in the two 

 preceding specimens, and the last premolar presents a modi- 

 fication in the disposition of the fossettes, to be noticed in 

 the sequel. The specimen belongs to the Swansea Museum, 

 and was discovered by Colonel Wood in ' Bacon Hole.' The 

 enamel in all the teeth is invested with a very thick layer of 

 cement. 1 



Pigs. 3, 4, and 5 of PL XVII. represent different views of 

 a detached germ of the last true molar, upper jaw, left side, 

 which has not yet come into use. It is free from any coat 

 of cement, thus presenting all the folds and depressions of 

 the enamel-shell in a perfect manner. 



Pig. 3 of PL XVI. represents a detached penultimate 

 molar of the left side, being the counterpart, from the opposite 

 side, of the tooth (m. 2) represented in fig. 1 of the same plate. 



These specimens are all drawn two-thirds or three- 

 fourths of the natural size, and taken together they furnish 

 a complete view of the characters of the upper molars, with 



1 The dimensions of this specimen 

 aro given in Dr. Falconer's note-book 

 as follows : — 



'Length of thrco molars, 5'9 in. Length 

 of last molar, outer surface, 2'9 in. 



Width of ditto, in front, 2-2 in. Length 

 of penultimate, oiiter surfaco, 2 - 2 in. 

 Width of ditto, in front, 2-3 in. Length 

 of last premolar, broken, l*7o in.' — [Ed.] 



