456 LOWER VERTEBRATES. 



sides of the body and liidiiig it, as it were, under the eaves of the shell. Chelys 

 mataniata, the remarkable fimbriated or bearded-turtle, belongs to this family. This 

 is one of the most peculiar creations of nature, in oddity being exceeded by none. 

 It iniiabits tlio warm fresh-water jiuols of the troiiical jiortions of South America, and 

 has been, until of late years, quite abundantly found, tliough, from the unceasing draft 

 made upon it for food, it is now quite uncommon. It is said to be a carnivorous ani- 

 mal, lying in wait, concealed by the rushes of some quiet body of water, for an un- 

 suspecting lish or rej)tilc, or possibly a bi'ood of young ducks, which it captures by a 

 (juick extension of its neck. It grows to a considerable size, sometimes reaching the 

 length of three feet. As is shown in the engraving, the snout is greatly j)rolonged, 

 and the sides of the head and ridges of the neck are 2)rovidcd with peculiar prolonga- 

 tions of the skin, the true office of which is not known. An allied form, Ili/drasjns 

 maximilianii, also inhabiting Brazil, has been given a family value l)y some naturalists. 

 The figure illustrating this .•niimal shows the peculiar manner in which the head and 

 elongated neck is protected by being applied to the side of the body rather than being 

 withdrawn into the carapax. 



The family Pelomedusid-e includes the single genus Pelomedusa, wliich is charac- 

 terized by having but two series of phalanges instead of the usual number, three. 

 P. siibnrfa and other species inhabit South Africa. 



The highest family of the order, SternothzERID-e, is based on the j)eculiar structure 

 of the anterior divisions of the plastron, which are separated transversely, giving the 

 .•Miimals ten plates instead of the usual number, eight. This jieculiarity is similar to 

 that presented by the genus Plenrvdira. 



Order V. — RHYNCOCEPHALIA. 



The fifth order of reptiles includes a small number of animals resembling in gen- 

 eral outline some of the lizards, though jjresenting several internal characteristics, as 

 the possession of bi-concave vertebras and immovable quadrate bones, which are at 

 variance with the forms already treated and are of ordinal value. But a single rep- 

 resentative, the Ilatteria or Spheiiodon of New Zealand, is still living, thougli the 

 paleontologist has brought to light the bones of a few pre-existing fonns. 



The Hatteria is one of those isolated animals which, from the j)eculiarity of its 

 structure, is of interest to the anatomist ; as throwing light on the more obscure points 

 in the structui-e of fossil relatives, and, to the systematic zoologist, fills, as a single 

 specimen, the place of species, genus, family, and order. The general apjiearance is 

 igua]ia-like. The tail is compressed and cresteil, and, like many lizards, being of a 

 brittle nature, is often found reproduced, but without vertebral segmentation. The 

 general color is, above, dull olive-green s]iotted with yellow, and below, whitish. Be- 

 sides the peculiar fish-like vertebra? and rigid quadrate bones, some of tlie ribs are 

 provided medially with uncinate processes, resembling those of crocodiles, if not more 

 strongly those of birds. Third and intermediate portions, like those found in the 

 monotremes and sloths, unite the dorsal with the sternal costw. Teeth occur not only 

 on the jaws, but also on the palatine bones, where they are arranged in a regular series, 

 parallel with those of the maxillaries. The total length seldom exceeds twenty 

 inches. At one time these animals were to be found in abundance along the rocky 

 shores and small islands of the New Zealand coast, where they lived in the crevices of 

 the rocks, or in small burrows of their own constr\u'tion. Of late, however, being 



