1856.] OWEN RED CRAG MAMMALS. 219 



terminate near the entry of the posterior valley a, where, however, it 

 has been worn away by pressure against the adjoining tooth. There 

 is no evidence of such a ridge in any of the upper molars of the 

 Rhinoceros tichorhinus. In the excellent figures of the upper 

 molars of the Rhinoceros Schleiermacheri, of the natural size, given 

 by Prof. Kaup *, the third and fourth molars exhibit a similar basal 

 ridge to that in the Rhinoceros megarhinus^ and in the crag-tooth, 

 fig. 1. 



In the greater depth and width of the entry to the internal (6) and 

 posterior {a) valleys, the crag-tooth resembles the pliocene and 

 miocene Rhinoceroses above-cited, and differs from the pleistocene 

 Rhinoceros tichorhinus ; in which, owing to the entry of the corre- 

 sponding valleys being relatively shallower, and those valleys deepening 

 more as they penetrate the crown, they are sooner converted into pits 

 circumscribed by islands of enamel, as shown in the teeth, figs. 1, 2, 

 & 4, pi. 6, and in figs. 1 & 6, pi. 13, of the * Ossemens Fossiles' of 

 Cuvier, in the paper by Dr. Buckland in the * Philosophical Trans- 

 actions ' for 1822, pi. 21. fig. 3, and in my ^British Fossil Mam- 

 malia,' figs. 122 & 126. 



The internal valley, b, is bilobed in the Rhinoceros tichorhinus, 

 or bends back so abruptly at its termination, that that termination 

 becomes insulated by attrition from the rest of the valley, as in some 

 of the figures above-cited ; such a change does not take place in the 

 Rhinoceros megarhinus and Rh. Schleiermacheri ; in the latter the 

 end of the valley h slightly expands, and sometimes it is festooned by 

 small processes of enamel and dentine re-entering it, as is shown in 

 the crag-tooth, fig. 1, h, and in the penultimate upper molar of the 

 Rhinoceros Schleiermacheri, figured in tab. 9. fig. 5, of Prof. Kaup's 

 excellent work above quoted. 



Prof. Christol does not represent this structure in any of the 

 molars of his Rhinoceros megarhinus ; but in the sixth (penultimate 

 or second true) molar, attributed by M. Gervais to the same species, 

 and figured, of half the natural size, in the ' Paleontologie Fran9aise,' 

 pi. 2. fig. 5, the same modification of the end of the valley, 6, re- 

 appears, as is shown in the corresponding tooth of the Rhinoceros 

 Schleiermacheri. From these differences I conclude that the fossil 

 tooth from the Red Crag of Wolverston does not belong to the 

 species of Rhinoceros {Rh. tichorhinus^ which is associated in our 

 pleistocene gravels, drifts, and bone-caves with the Elephas primi- 

 genius, but that it belongs to a species much more nearly allied to, 

 if not identical with, either the Rhinoceros megarhinus of the older 

 pliocene formations, near Montpellier, or the Rhinoceros Schleierma- 

 cheri of the miocene formations near Darmstadt. 



The second example of the upper molar of a Rhinoceros, from 

 the Red Crag of Suffolk, fig. 2, is also from the right side ; but 

 the outer third of the crown is broken away together with the 

 base of the tooth. It is worn down more deeply than the preceding 

 molar, the valley b being insulated, and the valley a connected by an 

 isthmus of little more than a line in breadth with the outer wall of 



* Op. cit. tab. 11. fig. 5. 



