322 
the two sides of the river Layon, in a calcareous bed formed of fossil 
fragments of shells. These bones were considerably mutilated, but 
were known to belong to phocse, lamantins, and cetacea. Ann. du 
Mus. Tome xtn. p. 273. 
Although these bones could be arranged under their proper genera, 
the species to which they belonged could not be ascertained. Thus a 
fossil skull, found with these bones, was determined to be that of a ma- 
natus, but of one different from those which are known. Three ribs, 
bearing the cylindrical form peculiar to the ribs of these animals, were 
found in the Commune of Capians, about ten leagues from Bourdeaux. 
The bones which Esper found in the caverns of Franconia, and 
which he thought were the bones of seals, are undoubtedly the bones 
of terrestrial carnivorous animals. But some of the bones found by 
M. Renou, of Angers, were decidedly the bones of a seal, and twice 
and a half as large as those of the common seal, P. vitulina, which 
is now seen on the coast of France. 
No decided remains of the Morse, or Walrus, Trichecus rosmarus, 
have been discovered in a mineralized state. Leibnitz imagined the 
elephantine remains of Siberia to have belonged to the “Walrus ; and 
Walch, Wallerius and Gmelin, have supposed the fossil jaw found in 
the neighbourhood of Bologna, Be Monum. diluv. in agro bonon. 
detedo, to have belonged to the walrus ; but Cuvier has plainly shown, 
that it is the remains of a small species of the mammoth ( Mastodon ), 
as will be more particularly noticed in a succeeding letter. 
I am unable to speak decidedly of a fossil tooth, said to be found in a 
bed of alluvial matters, in Norfolk. Its substance is very considerably 
changed : it is about fifteen inches in length, and appears to be nearly 
perfect at its extremities ; although one side of it, and a considerable 
portion of its internal substance, is removed. The fineness of its grain 
and its edge not manifesting the peculiar lozenge -formed decussations 
observable in the ivory of the elephant and of the mammoth (Mastodon), 
with the size and form of the tooth, lead to the suspicion of its having 
belonged to an animal of this genus. On the other hand, neither its 
