The little book of British quadrupeds

The Water Rat is somewhat smaller than the common brown Rat; its head and nose are thicker; its eyes are small; its ears short, scarcely appearing through the hair; its teeth are large, strong and yellow. In an old one, the lower front teeth measure somewhat more than half an inch in length. The hair on its head and body is thicker and longer than that of the common Rat, and chiefly of a dark brown colour, mixed with red; the belly is grey; the tail five inches long, covered with short black hairs, and the tip of the tail is white. The Water Rat generally frequents the sides of rivers, ponds, and ditches, where it burrows, and forms its nest. It feeds on frogs, small fish, and spawn; swims and dives remarkably fast; and can continue a long time under water.

The Musk Rat somewhat resembles the one just described. The eyes are large; the ears short, rounded, and covered both inside and outside with hair. Its fur is soft, glossy, and of a reddish-brown colour; and beneath this is a much finer fur or thick down, which is very useful in the manufacture of hats. The tail is flattened and covered with scales.