transverse furrows. ‘There are no true teeth; but
at the back of each mandible, in the ordinary
place of molars, are two horny appendages, resembling teeth, but without roots, which are of a
somewhat square form, and have a broad, uneven
surface, calculated for crushing rather than grinding. Beneath the skin of the face are capacious
cheek-pouches, for the carrying of food. The
eyes are bright, but very small, and situated high
on the forehead. ‘The ears are mere orifices,
easily discernible during life, being opened and
closed by the will of the animal, but scarcely to
be perceived in dead specimens.
On both the fore and hind-feet are five well-developed toes, all armed with long, curved, and pointed claws. They are all connected by a leathery web, which in the fore-feet extends considerably beyond the tips of the claws, presenting a broad and powerful oar when in the water, but folded back when the animal is engaged in digging the earth. On the hind-feet the web reaches only to the extremities of the toes. The hind-feet are armed also with a stout, sharp, moveable spur, which was formerly regarded as highly poisonous; the experiments of Mr. Bennett, however, prove that no use is made of it in defence, and that scratches produced accidentally by it, are followed by no ill effects. In the male alone is this spur well developed.
The body is somewhat flattened, bearing some resemblance to that of a small otter; the tail is broad and depressed.
Two species have been described under the names of Ornithorhynchus fuscus, and O. rufus; the distinctions, however, are very slight, the
