1870.] OWEN—CHINESE FOSSIL MAMMALS. 425 
The second specimen consists of a smaller proportion of the inner 
part of a penultimate or antepenultimate molar, with evidence of 
the notch or valley penetrating from the hinder side of the crown. 
The promontory, running from the postinternal lobe into the valley 
entering from the inner side of the crown, resembles in simplicity of 
form that of the preceding tooth. The ridge at the back part of the 
base of the postinternal lobe is likewise very thick. A small mam- 
milloid process projects near the entry to the valley e. The bases 
of the two inner fangs are preserved. 
A first molar (m 1), abraded to the base of the crown, agrees in 
size and in so much of character as 1s preserved with the foregoing 
specimens ; it exemplifies that of the valley ¢, inasmuch as, although 
the terminal bed is brought to the level of the grinding-surface, it 
is not insulated. ‘The outer side of the tooth is broken away. 
The outer enamel-wall (Pl. X XIX. fig. 3), with a small portion of 
adherent dentine, of a fourth upper molar, not forming part of any 
of the other three teeth, shows a strong vertical columnar bulge (a) 
terminating at the apex of the antexternal lobe, as. in Ahinoceros 
sumatranus; but it also has a second, well defined, but less prominent, 
vertical ridge (6) rising to the apex of the postexternal lobe, the 
two ridges dividing the outer surface of the crown into three facets. 
In Rhinoceros sumatranus this character distinguishes the pre- 
molars from the true molars; but the second or hinder ridge of 
the outer enamel-wall is less defined in that species; and in the 
present tooth the middle facet is not uniformly concave from 
before backward, but undulates, through the projection, near the 
hinder boundary ridge, of a lower longitudinal rising of enamel. 
The apices of the two outer lobes (a, 6) are more prominent than in 
Rhinoceros sumatranus; and the angular contour of that border of 
the tooth makes a closer resemblance than in Rhinoceroses generally 
to the outline of the same part in Palewotherium. 
The fossil upper molars of the species of Hhinoceros from Ava, 
figured by Clift*, are much worn; but, as in the Chinese molar in 
the same condition, the closed and somewhat deeper end of the 
valley (¢) is not insulated, as it is in all the Siwahk kinds at the 
same stage of attrition. The Avan teeth, however, indicate a larger 
animal than the Chinese species, and are more satisfactorily differen- 
tiated by the absence of the second longitudinal ridge (Pl. XXIX. 
fig. 3,6) on the outer wall of enamel. 
From Rhinoceros platyrhinus, Fr.t, the Chinese species differs, 
both in the contour of the outer wall of the upper molar, and in 
the simplicity of the promontory. From Rhinoceros sivalensis, 
Rh. sinensis differs in the contour of the outer wall, in the thicker 
or broader promontory, and in the more uniform depth of the valley 
(e), wherebyits termination is not insulated as in the specimen figured 
in pl. 75. fig. 5 of the ‘Fauna Antiqua Sivalensis. The same 
differences forbid a reference of the Chinese upper molars to 2thino- 
ceros paleindicus; and both this and the Lhinoceros sivalensis were 
* Trans. Geol. Soc. second series, vol. ii. pl. 40. fig. 1. 
+ Fauna Antiqua Sivalensis, pl. 72. fig. 6. 
VOL. XXVI,—PART I. 26 
