* Genus Lutea, Linn.
Dr. Gray, in the Catalogue of CarniYorous Mammalia,1 separates Enhydna
bitris, or the. Sea Otter, as a distinct tribe from the true Otters, under the name
Enhydrina. The Lutrina or true Otters he refers to two groups depending on the
character of their tails; the first having the tail rounded on the sides, and the second
having the tail with a cord-like ridge on each side. The first of the groups is
broken up into genera, viz., Bara/ngia, Lontra, Lutra, Nutria, Lutronectes, Aonyx,
Hydrogale, and Latax; and the second group contains only the genus Pteronura.
These first eight genera are again referred to sub-divisions: one, including the
first sitt genera, is said to be distinguished by the palms and soles of the feet being
bald between the pads, and the palm pads, without any small circular warts on
their hinder edges; the other, which includes the last two genera, has the under
surface of the feet, between the finger pads and palms, sprinkled with scattered, soft
hairs, and the inner part of the under surface of the two inner hind toes with a
band of close, short, soft hairs. In some of the animals of the first group, the nose
is clothed with hair, while in others it is bald, which is also the character of the
nose of the animals of the second group.
The ridge-like cord on the tail of Pterormra, Gray, or Pterura of Wiegmann,2
is of a doubtful nature, and is not a sufficient character to give the animal generic
rank, as the tails of other Otters are not rounded, but have sharp margins; and Dr.
Gray seems ultimately to have allowed this. The cranium and teeth also exactly
conform to the true Lutrine type, the only remarkable feature of the skull being its
great size; but other Otters—e. g., Lutra mimguis and Lutra braziliensis—are quite
as remarkable in this respect.
On examining the feet of the Otters referred by Gray to the secondary subdivision
of the Lutrma, I observe that the greater number were characterised by the
presence of scattered small hairs on the under surface of the webs, so that the
absence or presence of scattered hairs on the palms and soles must be abandoned as
a means of separating the genera.
The sub-division of the first of the two primary groups is again sub-divided
into two minor groups, the first distinguished by its hairy, and the second by its
bald nose. But the first of these is subjected to a further sub-division, in which
the nose is said to be perfectly hairy in one, and partially bald in the other. To the
hairy sub-division the genus Bara/ngia is referred, but I observe that the nose
of the type of this genus is not perfectly clad, as the centre between the nostrils
is bare, and Cantor mentions that the hair becomes partially rubbed off with age;
but in a full-grown animal in the India Museum, London, the nose is still
hairy.
Before adverting to these genera more particularly, it may be stated that the
teeth of all exhibit a remarkable conformity of structure, and that they do not offer,
1 Cat. Carniv. &c., B. M. 1869, pp. 100-118. * Archiv. fur Naturgesch. 1838, p. 392, pi. 10r
as far as my observations go, and I have examined eacb genus, a single character bv
winch to separate them genericaUy one from the other, the only differ«,,.,, being as
was to he looked for, that in such large animals as Lutra braziliensis and L . smd-
bacbn, the teeth are very much larger than in the skulls of the smaller Otters, such
a. £ vulgans; the only exception being that the molar teeth of the small-clawed
Otters are proportionally larger than in their compeers with long claws.
_With regard to the cranial characters which Dr. Gray regarded as distinctive
of Barwngia, it must be remarked that the skull from which he derived them is that
of a young animal, and that the little definition of the orbital processes is entirely
a character of youth—a view of the question which is fully home out by an insnec
iron of the skull of an adult animal which I have had the opportunity of examining,
as Mr. Moore of the India Museum, London, permitted me to remove the skull from
Cantor’s specimen, Plate XII, figs. 4 to 6. This skull has the orbital processes quite
as well developed as m Lutra vulgaris, from which it does not differ genetically. The
nasal bones of Otters, as of other allied forms, are subject to considerable variation
and I cannot detect that they materially differ in this species from those of the ordinarv
Otter, or that the premaxillse are more slender than in Lutra* I do not therefore
see any character by which this hairy-nosed species can be separated genetically
from Lutra, -because the singular fact of a hairy nose is not sufficient of itself
to give the animal generic rank, while at the same time it is a good specific
character by which the animal can be recognised among Asiatic Otters.
H R | § Grar » Us Catalogue1 describes under the genus Baramgia a small Otter
skull from Nepal with abraded, superior orbital processes, but regarding which
ere is no.evidence that it.helongs to an Otter with a haired nose,,because the skull
of the hairy-nosed Otter does not differ genetically from the skull of Lutra. This
form he doubtfully referred to Barangia under the specific term nepalensis..
The skull of the genus Lontra of ,Dr. Gray’s catalogue2resembles thatof Aonvx,
m its general form and the proportions of its different parts, but on an enlarged
S? f 6' molara’ als0’ aeir relative proportions conform to Aonyx, but the
other structural features of the animal do not entitle it to be separated from Lutra
The skuh of Lontra brasiliensis, Gray, is so closely allied to a skull that stands in
the British Museum as Nutria felma> that they might be one and the same species
and I fail to detect the , characters by which this genus is said to be . at once known’
from the others. The dentition of Nutría is identical with that of Lutra.
. ^ ™ u m of tjhe genus Latax, Gray,1 is essentially that of Lutra. The eon
cavity of the palate ascribed to it is very little more than may not unfrequentlv
be o^sOTved m Lutra vulgaris, and the last molar holds the proportion to the penul
tímate tooth that exists in Aonyx.
The skull of the South African Hydrogale is intermediate between.that of
Lutra and Aonyx, and its distinguishing features are the narrow character of the
inter-orbital portion and the absence of the post-orbital frontal process, the lower or
W 101. . •L .c y .m .
B 2