| OCR Text |
Show 212 DR. J. E. GRAY ON THE TORTOISES. [Mar. 11, 2. The front edge of the lower jaw narrow ; the inner surface of the front part of the jaw shelving inwards. a. In some of these the hinder part of the sides of the edge is more or less expanded and flattened out into an alveolar disk : Dogania, Potamochelys, Cyclanosteus. b. In others the sides of the edge are as narrow as the front part : Tyrse, Platypeltis, Callinia. The genera of the family may be thus arranged :- Section I. The head ovate or oblong, face moderate. Skull strong, thick, solid. A. The sternum contracted behind, without any flaps over the hind legs. a. Nostrils small, far apart, on the sides of the end of the proboscis. 1. A M Y D A . A. mutica. b. Nostrils moderate, circular, close together in the middle of the end of the proboscis, with a small lobe on the inner side. * Head short, forehead convex. The front and sides of the lower jaw with a broad, expanded, flat or slightly concave alveolar surface. Anterior palatine groove deep. cc. Sternal callosities six. 2. LANDEMANIA. L. irrorata. p. Sternal callosities four. 3. T R I O N Y X . Head short, forehead convex. Anterior palatine groove broad, shallow. Alveolar surface of the lower jaw broad, as wide in front as on the sides, rather concave, with a central longitudinal ridge in front. Hab. Asia. T gangetica. 4. F O R D I A . Head short, forehead convex. Anterior palatine groove narrow, linear, deep. Alveolar surface of the lower jaw very broad, as wide in front as on the sides, flat, granular. Hab. A-Vfrica. F. africana. 5. SARBIERIA. Head rather elongate. Anterior palatine groove (iu beak) narrow, deep, gradually becoming wider behind (in skull). Alveolar surface (of beak) in lower jaw regularly concave and smooth in front, and slightly concave on the sides. Odd anterior bone of dorsal disk free and smooth in the young specimens. S. frenata. y. Sternal callosities two, lateral. 6. A\SPILUS. Head oblong, elongate. Alveolar surface of the upper jaw wider behind ; of the lower jaw broail, rather wider in front |
