1847.] OWEN ON ENGLISH EOCENE MAMMALIA. 29 
of the canines and incisors are also preserved, showing the dental 
formula of the upper jaw of the present genus to be— 
> ae a ae AE eae ad 
o) — ee 
a 
5) 
The grinding surface of the true molars differs from that of the 
same teeth in the Paleotherium Aurelianense : the penultimate molar 
M 2 in the specimen (fig. 2) has the enamelled summits of the ridges 
abraded to the same extent as in the (apparently) penultimate molar 
of the Paleotherium Aurelianense figured by Cuvier * (fig. 6) ; and 
shows the following distinctions :—there is no small insulated che- 
vron-shaped lobe like that marked c, fig. 6, in the depression at the 
posterior borders between the ridges o! and ¢’: the anterior ridge (fig. 2, 
M 2, 2) is divided by a notch, and its inner lobate termination (p) pre- 
sents on its summit a distinct island of dentine surrounded by enamel : 
the anterior and external angle is not produced forwards, as repre- 
sented in Cuvier’s figure, which gives a peculiar character to that 
tooth not alluded to by Cuvier, but which I have not observed in any 
specimens or figures of the corresponding molar in any known species 
of Paleotherium. 'The Paleotherioid from Hordle is also smaller 
than the Orleans species. 
Nothing, therefore, can be inferred as to the true dental formula 
of the Paleotherium Aurelianense, or of its claims to the generic ap- 
pellation of Anchitherium, from the ascertained dental formula of the 
upper jaw of the Paloplotherium from Hordle +. 
That this formula accurately gives the number and kind of the 
teeth of the upper jaw is proved by the following facts. The edentu- 
lous border of the jaw between the first premolar and the canine is 
entire on both sides, is sharp until its expansion to form the socket of 
the canine, and shows no trace of the socket of a shed or abortive 
false molar. The alveolar tract or ‘ process’ is also entire and termi- 
nates behind the last molar ; it does not bulge out backwards, as it 
would do if the germ of another molar had there been present. The 
fourth grinder (M 1, figs. 1 & 2) counting backwards is more worn 
than the three which precede it, showing that they had come later 
into place ; and, to determine whether the worn fourth grinder was 
the last of four milk-molars, or the first of the three true molars, I 
i. peels du Muséum, iii. (1804) pl. 35. fig. 10. Ossemens Fossiles, pl. 67. 
ae 
t Since this paper was read at the Meeting of the Geological Society, I have 
had the opportunity of inspecting at Paris, through the kindness of M. Laurillard, 
the series of fossils of the Paleotherium Aurelianense, which has been enriched, 
since the time of Cuvier, by the discoveries of the zealous and learned M. Lartet 
of remains of the same or a very closely allied species in the Eocene deposits at 
Sansans. These remains, some of which M. de Blainville has recently described 
and figured in the last published (21st) fasciculus of his ‘ Ostéographie’ (pp. 51, 
75, pl. 3.), prove the number of premolars to be the same in both jaws as in the 
typical Paleotheres, viz. =. The indefatigable author of that beautiful work, 
though recognising the specific identity of the Paleotherium equinum of Lartet 
with the Paleotherium Aurelianense, Cuvier, proposes nevertheless another syno- 
nym—Paleotherium hippoitdes—for the species.— Deceméer 1847. 
