364 RHINOCEROS. 



Extreme length of the line of 6 molars on the left side, measured from the base 

 outside of the penultimate p.m. to the posterior boundary of the rudimentary pit at 

 base of last molar, 9'1 in. Length of ditto on right side from anterior margin of 

 alveolus of dropped first premolar to posterior boundary of last true molar, 9'5 in. 

 Length of last three premolars, left side at top of crown, outside, 4-3 in. Length 

 of three true molars to posterior boundary of last, left side, 5-4 in. Length from 

 the antepenultimate p.m., right side, to the posterior margin penultimate true 

 molar (to correspond with the Pisa cast), 7'7 in. Length of antepenultimate p.m. 

 left side, top of crown outside, T35 in. Extreme width at base of ditto, behind, 

 T6 in. Length of penultimate ditto ditto, left side, 1-55 in. Greatest width of 

 ditto in front at base, 2 - in. Length of last premolar in front at left side, 1'6 in. 

 Greatest width of ditto in front at base, 2 - l in. Length of crown "of penultimate 

 true molar (1*95, right side), 2- in. Greatest width of ditto at base in front, right, 

 22 in. Length of crown of ditto at base inside, 1*5 in. Length of crown of 

 penultimate true molar, right, outside, 2' in. Length of crown of ditto, inner side, 

 at base, 1"5 in. Greatest width at base in front of ditto, 2'2 in. Antero-posterior 

 diameter last true molar, left side, from anterior bourrelet, in front, to posterior 

 boundary of basal valley behind, 1*8 in. Transverse diameter of ditto, in front, 

 at base, 2-1 in. Interval between the anterior barrels of antepenultimate pre- 

 molars, 2'0o in. Interval between anterior barrels of last premolar at base, 2-8 

 in. Interval between anterior barrels, first true molar, 3 - in. Interval between 

 anterior barrels of penultimate true molar, 2'1 in. Interval between anterior barrels 

 of last molars, 2 - 85 in. 



Memo. — The above dimensions give the width of the palate. 



Length of diasteme in front of pre-antepenultimate premolar, right side, 1'75 in. 

 Interval between the diastemal ridges in front of first premolar, 2 - l in. (These 

 comprise the principal dimensions of the teeth.) Height of zygomatic arch, left 

 side, 1 - 8 in. Width of zygomatic fossa, left side, 3 - 5 in. 



Description of the Teeth on right side. — There were 4 premolars. 

 This is distinctly shown on the right side by the triple farjg-pits of the 

 pre-antepenultimate or p.m. 1, viz. one in front and two separate ones 

 behind : they are more or less filled np. 



P.m. 2, the antepenultimate premolar, is quite entire on both sides, 

 and in nearly the same stage of wear. The discs of the two inner 

 barrels are distinct, and nearly of the same size ; the anterior barrel does 

 not form an isolated compressed cusp-shaped cone, as in Gervais' draw- 

 ings of R. leptorhinus. The disc forms a very compressed oval, which 

 is not confluent with the outer longitudinal disc. The disc of the 

 jiosterior barrel is wider, and it is connected by an isthmus with the 

 disc of the outer ridge, forming a kind of gourd-shaped outline. The 

 disc of the outer longitudinal ridge is not much advanced in wear, being 

 where broadest but - -±. The posterior valley is nearly quadrangular 

 in form and well defined, the posterior boundary being quite intact. 

 The great middle valley forms a large triangular fissure, into which 

 crochet processes are intruded from behind forwards. There is a 

 distinct cingulum to the base at the inside, but not in strong relief, 

 not so much so as the anterior talon. The outer surface of the crown 

 is convex, antero-posteriorly. 



P.m. 3, the penultimate premolar, right side. This tooth resembles 

 in form the antepenultimate, but is larger and more advanced in wear. 

 The discs of both barrels being confluent with the outer disc, it is much 

 broader in front than behind. The anterior outer vertical furrow is 

 well marked, the posterior valley is very much as in p.m. 2. The 

 great middle valley forms a large fissure which is divided into two 

 portions by the crochet processes, and an outer accessory plate is in- 

 truded from the longitudinal ridge ; one little ring of enamel is isolated 

 on the base of the crochet. 



