The Ornithorhynchus is only found in fresh-water lakes, of which there are many in the interior parts of the country, some three quarters of a mile long, and several hundred yards broad.  It does not swim upon the surface of the water, but comes up occasionally to breathe, which it does in the same manner as the turtle.  The natives sit upon the banks, with small wooden spears, and watch them every time they rise to the surface, till they get a proper opportunity of striking them.  This they do with much dexterity, and frequently succeed in catching them this way.

Governor Hunter saw a native watch one for above an hour before he attempted to spear it, which he did through the neck and fore leg:  when on shore, it used its claws with so much force that they were obliged to confine it between two pieces of board, while they were cutting off the barbs of the spear, to disengage it.  When let loose, it ran upon the ground with as much activity as a land tortoise; which is faster than the structure of its fore feet would have led us to believe.  It inhabits the banks of the lakes, and is supposed to feed in the muddy places which surround them; but the particular kind of food on which it subsists is not known.

The male is 171/2 inches in length, from the point of the bill to the extremity of the tail.  The bill is 21/4 inches long; and the tail, measuring from the anus, 41/2 inches.

The body of the animal is compressed, and nearly of the same general thickness throughout, except at the shoulders, where it is rather smaller.  The circumference of the body is 11 inches.  There is no fat deposited between the skin and the muscles.

In the female, the size of the body is rendered proportionally larger than that of the male, by a quantity of fat lying every where under the skin.

The male is of a very dark brown colour, on the back, legs, bill, and tall; the under surface of the neck and belly is of a silver grey.  In the female the colour is lighter.

The hair is made up of two kinds; a very thick fur, one half of an inch long, and a very uncommon kind of hair, three quarters of an inch long.  The portion next the root has the common appearance of hair; but for a quarter of an inch towards the point it becomes flat, giving it some faint resemblance to very fine feathers:  this portion has a gloss upon it; and when the hair is dry, the different reflections from the edges and surfaces of these longer hairs give the whole a very uncommon appearance.  The fur and hair upon the belly is longer than that upon the back.

Externally there is no appearance of the organs of generation in either sex; the orifice of the anus being a common opening to the rectum and prepuce in the male, and to the rectum and vagina in the female.

There was no appearance that could be detected, of nipples; although the skin on the belly of the female was examined with the utmost accuracy for that purpose.