PEXGELLT — Oy THE AGE OF THE DAETMOOE GEAXITES. 11 
sists of a pair of cones ; the inner one being rudimentary, the outer 
one of the same anteroposterior extent as the normal outer cone, but 
lower and thinner, and oblique in its position." It is this accessory 
lobe, which in the ruminant division of Artiodactyla is strongly de- 
veloped. 
In the AmpJiiiragulus communis, from the lacustrine marls of Eon- 
zon, near Puy-en-Yelay, the accessory lobe is more outwardly and 
obliquely developed than in Didymodou, and the same remark applies 
to the Xipliodon gracile. 
I have been slowly led to the conclusion that the specimen in 
question is not to be identified with any of these genera, from the 
lower Tertiary deposits. At the risk of burdening the overloaded 
terminology of the fossil herbivorous Ungulates with a new name, I 
have been led to give it generic distinction. The specific name 
Vauclusianum is derived from the locality. 
[Should it be placed amongst the Artiodactyles, under which order 
it seems to be categorized, its place will be found near to Dichobune, 
Acotherulum, and Aphelotherium. At the same time, there is a cer- 
tain resemblance to Tapir ul us, which should preclude us from confi- 
dently denying that it may have perhaps formed part of tlie family of 
small pachyderms, congeners of the great Lophiodoutoid Perisso- 
dactyles. 
ON THE AGE OF THE DARTMOOE GEANITES. 
By W. Penoellt, E.G.S. 
Though our science has risen above the stage from which she taught 
that all granites are parts of the original crust of the earth ; thougli 
she has advanced so far as to doubt whether, in all cases, the granitic 
was tlie first phase of rock-existence which tlie materials composing 
it assumed, and to entertain the question whether such rocks may 
not be the extreme form of metamorphism, which has obliterated ail 
traces of an earlier condition ; and though she may prudently decline 
to point out, in the large circle of her rocky acquaintances, one mass 
of crystalline unstratified rock which, as such, can be proved to be 
older than some known beds of mechanical origin ; it remains to be 
the rule rather than the exception to meet with persons, frequently 
well-informed, and not without an interest in geology, who still cling 
to the notion, or allow it to cling to them, that every mass of granite 
is a primitive rock, in the strict chronological import of the term ; 
and represents a period in the earth's history prior to the possible 
existence of sedimentary strata, or of organized beings. Indeed the 
opinion that granite is, in all cases, a primary rock, has so large a 
place in the public mind, that one might prudently hesitate before 
throwing such a question as " AVhat is the age of the Dartmoor 
granite?" before any audience having a very large admixture of the 
popuL^r element. 
