The La Plata Otter in its general colouring is of a somewhat deeper hue
than the European species, the cheeks and throat instead of being nearly
white are of a pale brown colour; the tail is longer in proportion, and
tapers more gradually; the tip of the muzzle is naked, but the hairless
portion is less than in that species, the boundary line between the
naked part and the hair of the top of the muzzle forming almost a
semicircle; the retiring extremities of this line touch the posterior
angle of the nostril on each side, whereas in the common otter the
boundary line of the hair of the muzzle is of a ｗ-like form. The skull
is figured in Plate 35, figs. 4, _a_, _b_, _c_, and _d_, and is compared
with that of _L. Chilensis_ in the next description.
“This specimen was killed by some fishermen a few miles from Maldonado,
near the mouth of the estuary of the Plata, where the water is quite
salt. I am not, however, by any means sure that it may not be a
fresh-water species, which had wandered from its proper station; in the
same manner as not unfrequently is the case with the _Hydrochærus
Capybara_. I am indebted to Mr. Chaffers, the master of the Beagle, for
having kindly presented me with this specimen.”—D.