outside of Woburn Park.

[Illustration: SKELETON OF A RHYTINA, OR ARCTIC SEA-COW
In the United States National Museum]

THE RHYTINA, (_Rhytina gigas_).--The most northerly Sirenian that (so
far as we know) ever inhabited the earth, lived on the Commander Islands
in the northern end of Behring Sea, and was exterminated by man, for its
oil and its flesh, about 1768. It was first made known to the world by
Steller, in 1741, and must have become extinct near the beginning of the
nineteenth century.

The rhytina belonged to the same mammalian Order as the manatee of
Florida and South America, and the dugong of Australia. The largest
manatee that Florida has produced, so far as we know, was thirteen feet
long. The rhytina attained a length of between thirty and thirty-five
feet, and a weight of 6,000 pounds or over. The flesh of this animal,
like that of the manatee and dugong, must have been edible, and surely
was prized by the hungry sailors and natives of its time. It is not
strange that such a species was quickly exterminated by man, in the
arctic regions. The wonder is that it ever existed at a latitude so
outrageous for a Sirenian, an animal which by all precedents should
prefer life in temperate or warm waters.

[Illustration: BURCHELL'S ZEBRA, IN THE U.S. NATIONAL MUSEUM
Now Believed to be Totally Extinct]

BURCHELL'S ZEBRA (_Equus burchelli typicus_).--The foundation type of
what now is the Burchell group of zebras, consisting of four or five
sub-species of the original species of _burchelli_, is an animal