386 RHINOCEROS. 



Obs. 4. — The antepenultimate premolar (p.m. 2) of the left side 

 in the Cortesi specimen resembles in the closest manner the corre- 

 sponding tooth represented by De Christol in fig. 27 of his memoir. 1 

 The anterior cusp forms in both an isolated compressed cone, the apex 

 of which is just beginning to be abraded, and the posterior barrel has its 

 edge ground down into a narrow crescentic band, which is alike in both. 

 The principal difference observed is, that the basal bourrelet is more 

 strongly represented in De Christol's figure than it is seen in Cortesi's. 



Obs. 5. — The lower jaw of Cortesi's specimen is seen to be in the most 

 fragile state of disintegration. On detaching a slab of the matrix, mea- 

 suring 3-^ inches by 8 beneath the second and third premolars (p.m. 2 

 and 3) on the left side, it was seen that the fibrous roots of herbaceous 

 plants had insinuated themselves between the matrix and the surface of 

 the jaw, forming a web, and that the bony mass of the latter was cracked 

 and fissured in every direction, penetrated by roots, and in a state of the 

 most rotten decay. The lower jaw was evidently discovered uncrushed. 

 A great mass of matrix is interposed between the rami from the sym- 

 physis on to behind the last molar, yielding the dimensions given in the 

 table (viz. Nos. 17 to 21). The details of the teeth in the lower jaw 

 are as follows : — There is not a trace of incisives, the beak being partly 

 damaged at its edge, where they might be looked for, and the diaste- 

 mal ridges being also abraded. The lower contour of the beak expan- 

 sion is disguised by a cake of matrix, which has vitiated both Cortesi's 

 and Brongniart's drawings ; otherwise it would be like Christol's fig. 6. 

 There is no trace on either side of an alveolus for the pre- antepenulti- 

 mate, but it is by no means certain that it may not have been there to 

 correspond with the tooth in the upper jaw. The antepenultimate 

 premolar present upon the left side consists of two crescents, both of 

 which are only in the slightest degree affected by wear. The lower 

 half of the anterior end bears a smooth surface, which appears to be 

 the disc of pressure against a pre-antepenultimate, which had dropped 

 out. This disc of pressure for the pre-antepenultimate of lower jaw, 

 left, occupies nearly half the height of the crown and is sagittate in 

 form, like a Celtic arrowhead of flint. From the broad surface of the 

 anterior end of the antepenultimate, and the appearance of a disc of 

 pressure at its base, I am convinced that there must have been a 

 pre-antepenultimate, corresponding with the upper one. The third 

 premolar is present upon both sides, and both the crescents are slightly 

 affected by wear, showing a narrow band of enamel all round. The 

 anterior crescent in each is elevated about half an inch above the plane 

 of the posterior crescent. The last premolar is wanting on either side, 

 its site being occupied by a mass of matrix ; the last milk molars had 

 probably just fallen out, and their successors may be embedded in the 

 jaw as germs. The two stumps of the fangs of the antepenultimate 

 premolar are seen on the right side, the crown being broken off. 



The first and second true molars are present on either side, both of 

 them being but slightly affected by wear. The anterior division of 

 each yields a horse-shoe pattern, of which the front limb is much 

 shorter than the hind one. The posterior division yields a crescent with 

 but a very slight curve. The last true molar on either side is wanting. 



The condition of the dentition in both the jaw and cranium shows 

 that they must have belonged to the same individual. 



1 Ann. des Sc. Nat. 2 me Ser. torn. iv. 1835. PI. iii. fig. 12. See antca, p. 328, 

 note. — [Ed.] 



