This is also described and figured by Milne-Edwards.
[NO. 194. PUTORIUS MOUPINENSIS.]
HABITAT.—Thibet.
DESCRIPTION.—Reddish-brown, white under the chin, and then again a patch on the chest.
We now come to the third group of the musteline animals, the most aquatic of all the Fissipedia—the Lutridæ or Otters—of which there are two great divisions, the common Otters (Lutra) and the Sea-Otters, (Enhydra). With the latter, a most interesting animal in all its ways, as well as most valuable on account of its fur, we have nothing to do. I am not aware that it is found in the tropics, but is a denizen of the North Pacific. Of Lutra we have several species in two genera. Dr. Gray has divided the Otters into no less than nine genera on three characteristics, the tail, feet, and muzzle, but these have been held open to objection. The classification most to be depended upon is the division of the tribe into long-clawed Otters (Lutra), and short or rudimentary-clawed Otters (Aonyx). The characteristics of the skulls confirm this arrangement, as the short-clawed Otters are distinguishable from the others by a shorter and more globose cranium and larger molars, and, as Dr. Anderson says, "the inner portion of the last molar being the largest part of the tooth, while in Lutra the outer exceeds the inner half; the almost general absence of the first upper premolar; and the rudimentary claws, which are associated with much more feebly-developed finger and toe bones, which are much tapered to a point, while in Lutra these bones are strong and well developed." Gray has separated a genus, which he called Pteronura, on account of a flattened tail arising from a longitudinal ridge on each side, but this flattening of the tail is common to all the genera more or less.
| Otter's skull (side and under view). |
All the Otters, though active on land, are still only thoroughly at home in the water, and they are therefore specially constituted for such a mode of life. They have an elongated flattened form; webbed feet with short claws; compressed and tapering tail; dense fur of two kinds, one of long brown shining hairs; the under fur short and fine, impervious to wet, and well adapted for keeping an equality of temperature; the skull is peculiar, the brain case being very long, and compressed from above downwards; the facial portion forms only about one-fourth of the extreme length; the teeth are strong and sharp; the upper flesh tooth very large.
Dental formula: Inc., 3—3/3—3; can., 1—1/1—1; premolars, 4—4/3—3; molars, 1—1/2—2.