158 Proceedings of the Royal Physical Society. 
sufficient to warrant the separation of the animal possessing 
it into distinct genus, then the present species is entitled to 
that place. 
It is as yet only known by the skull, which was sent by 
Mr Thomson to Mr Murray. Its dentition differs from that 
of our common otter, Lutra vulgaris, in having one fewer pre- 
molar in the upper jaw. Mr Murray had submitted it to 
Professor Owen, who believes it to be nondescript, and that it 
approaches Enhydra of Fleming (Phil, of Zool.) in having the 
first pre-molar suppressed above, but that the latter has also 
the first pre-molar suppressed below. It has, however, six in- 
cisors in the under jaw, while the sea otter, Enhydra^ has only 
four in the adult state, which the specimen in question has. 
It would appear to form an intermediate link between the 
true otter and the sea otter ; and its habitat in an estuary 
may therefore perhaps be thought suitable enough ; and it was 
in reference to this that Mr Murray proposed the above generic 
name for it — Anahyster (belonging to an estuary). 
Phacochcerus, (sp. 1) 
Dr Cleland has received a young individual of this genus ; 
there does not appear to be any essential difi'erence between 
it and the Cape of Good Hope and Mozambique species, Ph. 
jEtJiiopicus. But the individual is too young to allow an 
opinion to be given with confidence. 
Hippopotamus amphihius. — Lin. 
From the information received from the missionaries, there 
is good reason to believe that the hippopotamus is found in 
the Old Calabar River further up than the mission stations ; 
but no specimens, or portions of specimens, have yet been 
sent home. It may be a question whether there are more 
than one species of hippopotamus. It is generally supposed 
there is only one, but it has been found in rivers so widely, 
and apparently impassably, separated, that it would be noways 
surprising if more than one species shall yet be determined. 
Manatus Senegalensis. — Desmar. 
Several skulls of this most interesting animal have now 
found their way into this country from our Old Calabar friends. 
