464 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1914. 
the animal, when finally captured, had but one effective leg. The 
American Indians, before they became acquainted with the use of 
iron, used these formidable teeth of the beaver as gouges and chisels. 
In other respects also the animal is excellently adapted for this 
work. He readily stands upright on his hind legs, as may be seen 
in plate 22. This is the posture he assumes when gnawing 
around a tree in order to fell it. His forelegs and paws are capable 
of holding and clasping, very much as do the hands and arms of 
man. It is with these that he carries his load of twigs, stones, 
and mud with which he builds. His hind feet are powerful paddles, 
and he can use his flat, scaly tail to guide him in swimming. When 
alarmed, he gives a resounding slap upon the water with his tail, 
dives, and seeks the security of his lodge. 
Near the pen in which the beavers are confined are smaller inclo- 
sures for gnawing animals of similar habits, such as the muskrat and 
the coypu or nutria. 
The muskrat is a natural inhabitant of the park, colonies of them 
being found in several places along the banks of Rock Creek. More 
tolerant of civilization than his cousin the beaver, he is also more 
prolific, and is consequently found in considerable numbers through- 
out the United States. He is smaller than the beaver and, like him, 
lives in lodges made out of small twigs or in burrows hollowed in 
the banks of streams and ponds, the entrance being always under 
water. The fur is sold extensively, usually under some disguising 
name, as “‘river mink,” or “‘ Hudson seal.” 
The coypu, also called the nutria, the South American water rat, 
otter, or beaver, is a native of Argentina, Chile, and Peru. Its habits 
are like those of the muskrat. 
Adjoining the beavers’ inclosure is the sea-lion pool, an artificial 
basin some 96 feet long, 47 feet wide, and 6 feet deep, through which 
fresh water constantly flows. Visitors often ask whether these ani- 
mals—in a wild state found only in salt water—can properly thrive 
in such a location. There has been no difficulty in keeping them in 
good health, for, being air-breathing creatures, they do as well in 
fresh water as in salt, provided they get plenty of food and exercise. 
Two different species are shown—the California sea lion, familiar 
to those who have visited the Cliff House, near Golden Gate, San 
Francisco, and the northern or Steller sea lion, a larger animal found 
principally in Bering Sea. The California species emits a loud, sharp 
bark, which it keeps up almost incessantly and which reminds one 
more of a dog than a lion, while the northern animal makes a roaring 
noise, remotely resembling that of a lion. 
These animals swim with great rapidity and ease throughout the 
whole extent of the pool, gamboling and playing about each other, 
and it is interesting to see how expert they are in seizing the fish 
