CHELYS. REPTILES. 339 



in the sand. When turned on its back on shore it cannot recover itself. Turtles 

 feed in great numbers on the algae at the bottom of the sea ; and various modes of 

 taking them are practised when in this situation, swimming on the surface of the 

 water, or on shore. 



C. imbricata, Cuv. Imbricated or Hawksbill Turtle. Shell heart- 

 shaped, with thirteen imbricated semitransparent and variegated 

 scales on the disc ; marginal pieces twenty- five; head small ; neck 

 long ; beak narrow and sharp. 3 to 5 feet long. Inhabits seas of 

 the Torrid Zone.Shuw, iii. pi. 26. 

 This is the species which affords the tortoise shell of commerce. Fire is applied 



below the shell, to separate the plates from their bony support. Tortoise shell was 



extensively used to ornament furniture by the ancient Romans. 



C. Caouana, Cuv. Shell oval or heart-shaped, dentated on the mar- 

 gin, more or less brown or reddish, with fifteen scales on the disc, 

 the intermediate ones ridged posteriorly; point of the upper man- 

 dible hooked ; fore feet long and narrow. Inhabits the Mediter- 

 ranean Sea Cuv. Reg. An. ii. 13. 



C. coriacea, Cuv. Coriaceous Turtle. Body without scales, but 

 covered with a brown skin resembling leather ; upper part oval, 

 and pointed behind, with longitudinal prominent ridges. 7 to 8 

 feet long. Inhabits Mediterranean Sea. Shaw, iii. pi. 21. 

 This species grows to a large size, and has sometimes been taken on the coast of 



England. 



Gen. 6. CHELYS, Dumeril. 



Shell too small to receive the members ; mouth cleft across ; 

 lips fleshy, with the nose prolonged into a small trunk ; toes 

 webbed. 



C.Jimbriata, Cuv. Shell oval, subconvex, brown, rough with pyrami- 

 dal eminences; neck with fimbriated membranaceous appendages; 

 snout cylindrical, truncated ; disc of 13 semicircular pieces ; mar- 

 ginal pieces 25, almost square. 2 feet 3 inches long; shell 15 

 inches. Inhabits Guiana. Shaw, iii. pi. 18. 



Gen. 7. TKIONYX, Geoff. 



Lips fleshy ; nostrils prolonged into a cylindrical tube ; back- 

 plate destitute of scales, but covered with a coriaceous skin, 

 studded near each extremity with hard knobs ; only three of 

 the five toes with nails. 



T. Mgyptiacus, Geoff. Soft Tortoise of the Nile. Back slightly 

 convex, of a green colour, spotted with white. Inhabits the Nile, 

 and devours the young crocodiles when newly hatched. Ann. 

 du Mus. xiv. 1. 



T.ferox, Cuv. Soft Tortoise of America. Shell brownish, ovate, 

 osseous in the middle, cartilaginous on the margin, obscurely mark- 

 ed with five or six transverse bands, and granulated with small 

 warts, of larger size near the margin ; head small, trigonal ; snout 

 much lengthened ; nostrils tubular, prominent, 18 inches long. 

 Inhabits N. America. Shdrv, iii. pi. 17 



