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Show 1869.] DR. J. E. GRAY ON THE TORTOISES. 195 scure keels, the central one broad, and the lateral ones narrower, about one-fourth of the width of the shield from the upper edge. The back dull olive, the chest black, the underside of the margin pale yellowish. Toes strong, united in the skin to the claws, with a few shields above; claws acute, black. Tail moderate, conical, tapering at the end. The 1st vertebral plate rather longer than wide, narrowed behind, with a concave hinder edge; the 2nd, 3rd, and 4th vertebrals as wide as long, with a rounded front and an arched hinder edge, the 2nd and 3rd wider behind than in front, and the 4th wider in front than behind. This specimen chiefly differs from typical D. reevesii in the larger size, the larger head, and a difference in the form of the dorsal shield ; but all this may depend on age and nourishment; and what were considered adult D. reevesii may have been young animals. 3. DAMONIA HAMILTONII. Geoclemys hamiltonii, Gray, Cat. Shield Rept. p. 17. Skull (as seen through the skin in the stuffed specimen) ovate trigonal, sides flattened ; orbit lateral, rather large; crown rhombic, rather convex in the middle, concave over the orbits, produced behind, about once and a half as long from the back edge of the orbit as from that point to the tip of the nose ; zygomatic arch very short, broad, confluent with the crown above, and much wider than the orbit in front, as wide as the tympanic cavity behind; sheath of the upper jaw simple, without any central hook ; lower jaw strong, convex, and covered with a horny sheath in front; toes enclosed in the skin to the claws, with band-like shields above, claws small. A specimen in spirits in the British Museum. The head moderate ; nose with each nostril in an oblong soft space; the upper beak with a simple short edge, rounded in front; lower beak with an acute produced centre. Alveolar surface of the upper jaw wide, linear, convex and rugose on the sides; alveolar surface of the front of the lower jaw broad, rugose, concave in the upper surface, narrow on the sides. Toes broadly webbed, crenulated on the edges, with a series of hexangular larger scales on the upper surface. This animal has the feet of Batagur; but the cavity of the skull is not contracted at the ends as in that group. 4. DAMONIA NIGRICANS. Emys nigricans, Gray, Cat. Shield Rept. p. 20, t. 6. Skull (as seen through the skin of the stuffed specimen) oblong triangular, sides of face flattish; orbit lateral, rather large; crown nearly flat, with an arched hinder edge, which is about as far behind the hinder edge of the orbit as that part is from the end of the nose; zygomatic arch flat, as wide in front as the back edge of the orbit,' and as the front edge of the tympanic cavity behind; the sheath of the upper jaw rather notched at the tip, with a simple edge; lower jaw broad, convex, and covered with a broad horny sheath in front. Toes slightly webbed to the claws. |
