48 AMPHITHERID&. 
cuspid, according to the species. M.M. Agassiz and De 
Blainville have supposed that the Stonesfield fossils pre- 
sented a form of tooth resembling most those of such seals 
amongst Mammalia; but the teeth of all the Seal-tribe 
offer a well-marked peculiarity in their thick and ven- 
tricose fangs, to which character those of the Amphithe- 
rium offer no approximation, but, on the contrary, have 
long and slender fangs, as in the small marsupial and 
placental Jnsectivora : besides, no species of Seal presents 
the backward prolongation of the angle of the jaw demon- 
strated by the fossil Amphitheria. 
The term ‘ Amphibia,’ in the concluding summary of 
M. de Blainville’s second memoir, has reference not to the 
cold-blooded Amphibia of Linneus and the German natu- 
ralists, but to the above-cited and last-expressed opinion 
of M. Agassiz, who, admitting the Stonesfield fossils to be 
certainly those of mammals, rejects them from the marsu- 
pial and insectivorous orders, observing that ‘‘ each sepa- 
rate tooth resembles the greater part of those of seals, 
near which group (amphibious Carnivora) the animal to 
which the jaws belonged should form a distinct genus. 
In fact,” adds M. Agassiz, “the aspect of these fossil 
fragments is so peculiar, that it draws our attention to- 
wards aquatic animals rather than away from them.” 
But, in addition to the anatomical objections above 
adduced, it may be urged, that, though an extinct mam- 
miferous animal, not larger than the water-shrew, should 
have been of aquatic habits, it does not follow that, there- 
fore, it was piscivorous, and endowed with the instincts 
and organization of a Seal; in the absence of any 
evidence of the locomotive extremities, the affinity of 
the diminutive Mammalia of the Stonesfield epoch to the 
Phocide, could, at best, but be matter of conjecture, and 
