6 NEW-YORK FAUNA. 



THE SOFT-SHELLED TURTLE 



Trionyx ferox. 



PLATE VI. FIG. 11. Young. — (CABINET OF THE LYCEUM.) 



Testudofcrox et eartilaginea. Gmelin, Syst. Nat. 



The Soft-shelled Tortoise. Garden, Phil. Transac. 1771, p. 226. 



River Tortoise. Penn. Arct. Zoology', Supplement, p. 78. 



La Tortue de Pennant. Daudin, Hist. Rept. Vol. 2, p. 68, pi. 18, fig. 2. 



Trionyx spiniferus. Lesuedr, Mem. Mus. Vol. 15, p. 258, pi. 6, a, b, c. 



T.ferox. Say, Ac. Sc. Vol. 4, p. 218. Le Conte, Ann. Lye. Vol. 3, p. 93. Harlan, Med. and Phys. p. 158 



T platypcltis. Fitzing. 



T. amyda. Schweigg. 



Trionyx ferox. Holbeook, Am. Herpetology, Vol. 2, p. 11, pi. 1. 



T.ferox. Kirtland, Report on the Zoology of Ohio. 



Characteristics. Dusky brown. Orbicular ; little elevated ; the anterior margin with cuticu- 

 lar processes. Fore feet with three squamous folds in front, and two 

 oblong tubercles behind. Young, with ocellate spots. Length 9-12 

 inches. 



Description. Shell entire, orbicular, bony in the central parts, and cartilaginous on the mar- 

 gins. The anterior margin in the adult with numerous pointed tubercles, which may be faintly 

 and distantly traced in the young. A series of raised and tuberculated lines on the disk in 

 the adult. Under a lens, the surface of the shell appears divided into minute compartments, 

 in which there are two concentric rings, including a small rounded central elevation ; these 

 are barely sensible to the touch. Sternum cruciform, osseous in the middle. Head large, 

 tapering acutely to the nose, which is long and flexible, with the nostrils nearly terminal. 

 Eyes prominent, contiguous, and almost vertical. Mouth cleft behind the eyes ; jaws narrow, 

 partly covered by the lips, which are thickened on the sides. Neck long, smooth, with a gular 

 fold. Legs long and slender, palmate, five-toed ; the web extending over the two clawless 

 toes on both feet, and high up along the posterior margin of the hind foot. Tail short, thick, 

 suddenly contracting to a point, and extending beyond the shell. Vent within • 5 of the 

 extremity of the tail. Claws robust, subtrigonal, nearly straight, the intermediate one on the 

 hind foot longest. 



Color. Shell dark slate, with numerous large ocellate spots, and with black dots chiefly 

 along the margin. Beneath, soiled white. Head slate, punctate with black on the summit 

 and sides. Nose light, or flesh-colored ; a white stripe, margined on each side with black, 

 proceeds from the posterior margin of the eyes, and is lost in the marblings on each side of 

 the neck. Chin and sides of the lower jaw, together with the feet and tail, varied with black 

 and white. Iridcs yellow, with a black medial stripe. 



Totallength, 9-0. Length of shell, 5-3. 



Ditto of head and neck, 3 - 0. Diameter of shell, 5 • 0. 



Ditto of tail, 1*7. Height of same, 1*4. 



