36G RHINOCEROS. 



contracted summit. The anterior barrel has a distinct basal bourrelet, 

 which is wanting in the posterior. The transverse valley is divided 

 into two parts by a crochet, advancing on the right side to meet an 

 accessory plate emitted from the anterior barrel. On the left side, 

 these two plates overlap. On the right side, an accessory plate is also 

 given off from the outer ridge, converging towards the crochet. The 

 most striking character about the tooth is, that, as in B. hemitcechus, 

 there is a distant rudiment of a posterior valley restricted to the base, 

 but not forming a well-defined cup with a distinct rim, as in that 

 species. This rudiment is distinctly shown on both sides, bounded 

 posteriorly by a basal cingulum. The basal bourrelet behind the 

 posterior barrel of the last true molar has barely emerged above the 

 alveolar margin. 



The enamel is smooth in all these teeth, and marked by beautiful, 

 fine, wavy, horizontal lines. There is not a trace of general superficial 

 rugosity, and not the slightest indication of a layer of cement. 



The outer surface of the enamel is traversed in a dendritic fashion, 

 by fine channels, like those which are attributed to the work of Marine 

 Sponges, but the formation out of which this specimen came is fresh 

 water. 



The bottom of the palatine echancrure comes in a line with the 

 middle of the posterior barrel of the penultimate true molar, and the 

 suborbitary foramen is immediately over the line of junction between 

 the penultimate and last premolars. The disc of the crochet of the 

 penultimate true molar is nearly as broad as that of the posterior 

 barrel, the crochet being very thick and simple. The anterior outer 

 vertical furrow is well pronounced in all the molars, from the penulti- 

 mate premolar to the last true molar inclusive. It is wide and shallow, 

 but the other vertical hollows are but very slightly pronounced by an 

 undulation of the surface. There is not the slightest indication of an 

 outer basal bourrelet, as seen in the Aceratherium incisivum of Kaup, 

 the outer surface being smooth, and nearly vertical throughout. 



Besides the above, there are casts in the Bologna Museum of several 

 of the principal specimens of Rhinoceros figured by Nesti, and a dupli- 

 cate cast of the Targioni Tazzetti cranium of the Florence Museum, 

 made by Savi for Pisa, and of which I got drawings. There are also 

 casts of the following bones: — A humerus, left side, very closely re- 

 sembling the figs. 1 and 2 of Cuvier's PI. X. Bhin., but more perfect, of 

 which the following are the dimensions : — 



Extreme length from top of tuberosity to tuberosity of outer condyle, 16 - 25 in. 

 From articulating head to middle of inner condyle, 14' in. Width of articular 

 surface of condyles, 3 - 4 in. Greatest width at inferior end, 5 - 2 in. Antero- 

 posterior diameter of inner condyle, 4 - l in. Greatest width of shaft at middle of 

 median tuberosity, 5 - l in. From sinus, at lower margin of middle tuberosity, to 

 top of great tuberosity, 7'2 in. Greatest constriction of shaft, below middle tube- 

 rosity, 2-2 in. Antero-posterior diameter of articular head and tuberosity, 4 - in. 

 Transverse diameter of articular head, about 3'7 in. 



Specimen of tibia and fibula, figured by Cuvier, PI. XL, Bhin., fig. 15. 



Extreme length of tibia at middle, about 14 - in. Transverse diameter of upper 

 articulating surface, 4-4 in. Antero-posterior ditto to inner margin of inner 

 articular surface, 4 - 8 in. Transverse diameter, lower articular head, including 

 fibula, 4'3 in. Antero-posterior diameter, inner articular cup, lower end of tibia, 

 2-8 in. Extreme length of fibula, 12-25 in. Transverse diameter of shaft of tibia, 

 at middle, 2-3 in. 



