Page:St. Nicholas, vol. 40.1 (1912-1913).djvu/107

1912.] hippo of the large species. Its skull is more convex, or rounded, on its upper surface, than that of ; its legs are longer and more slender in proportion, and its eyes do not “pop” out of its head, like those of the giant species. Another striking character is the long tail, which, in proportion, is about twice as long as that of its only living relative, H. amphibius.

“The face of the pygmy is relatively smaller than that of the large species, which brings the eyes nearer to the median line of the skull. The lower jaw of the pygmy bears only two incisor teeth, while the large species has four; and while the eyeballs of C. liberiensis are large, they are proportionally less elevated than those of the large hippo. As the latter swims nearly submerged, the eyes seem to float on the surface of the water like two shiny glass marbles.”

Pygmy elephants were discovered in 1905. The specimen at the New York Zoological Park is about fourteen years of age.



young people are undoubtedly familiar with the fact that the sponge, as we ordinarily know it, is in reality the flexible skeleton of a colony of salt-water animals.

The, a favorite and beautiful object found in many natural history collections, is a similar growth, only its skeleton is composed of silica, which in appearance resembles colorless glass. For this reason the name “glass-sponge”’ is often applied to the framework of this group of animals. The animal tissues of this sponge, as of others, cover the interlacing fibers of the framework which acts as a supporting structure.

The skeleton itself is sometimes formed, as in this example, of needle-like structures, which are called sponge-spicules. In other sponges, these spicules may take the form of