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 abundantly striped as to its body, neck and head, but with legs that are almost white and free from stripes. The sub-species have legs that are striped about half as much as the mountain zebra and the Grevy species. While there are Chapman zebras and Grant zebras in plenty, and of Crawshay's not a few, all these are forms that have developed northward of the range of the parent species, the original _Equus burchelli_. For half a century in South Africa the latter had been harried and driven and shot, and now it is gone, forever. Now, the museum people of the world are hungrily enumerating their mounted specimens, and live ones cannot be procured with money, because there are none! Already it is common talk that "the true Burchell zebra is extinct;" and unfortunately there is no good reason to doubt it. Even if there are a few now living in some remote nook of the Transvaal, or Zululand, or Portuguese East Africa, the chances are as 100 to 1 that they will not be suffered to bring back the species; and so, to Burchell's zebra, the world is to-day saying "Farewell!" [Illustration: THYLACINE OR TASMANIAN WOLF Now Being Exterminated by the Sheep Owners of Tasmania] * * * * * SPECIES OF LARGE MAMMALS ALMOST EXTINCT THE THYLACINE or TASMANIAN WOLF, (_Thylacinus cynocephalus_).--Four years ago, when Mr. W.H.D. Le Souef, Director of the Melbourne Zoological Garden (Australia), stood before the cage of the living thylacine in the New York Zoological Park, he first expressed surprise at the sight of the animal, then said: