CHELONIA. 171 



long, and weighing from seven to eight hundred pounds. Its flesh is highly 

 esteemed, and furnishes a wholesome and palatable supply of food to the 

 mariner in every latitude of the torrid zone. It feeds in large troops on the 

 sea-weed at the bottom of the ocean, and approaches the mouths of rivers to 

 respire. The eggs, which it deposits in the sand to receive the vivifying influence 

 of the sun, are excellent food ; its shell is of no value. 



Merrem has recently distinguished, by the name of SPHARGIS, those Che- 

 Ionia? whose shell is destitute of plates, and merely covered with a sort of 

 leather. Such is 



Test, coriacea, Lin. A very large species of the Mediterranean. Its shell 

 is oval and pointed behind, exhibiting three projecting longitudinal ridges. 



CHELVS, Dumeril. 



The Chelydes resemble fresh- water tortoises in their feet and nails ; and their 

 most dominant character consists in their mouth, which opens cross-wise, 

 being unarmed with the horny beak common to the other cheloniae, and similar 

 to that of certain batrachians, the pipa in particular. 



Test, fimbria, Gm. The shell studded with pyramidal elevations, and the 

 body edged all round with a pinked fringe. It is found in Guiana. 



TRIONYX, Geoffrey. 



The Soft-shelled Tortoises have no scales, the shell and sternum being 

 E" simply enveloped by a soft skin ; neither of those shells is 

 completely supported by bones, as the ribs do not extend 

 to the edge of the upper one, and are united with each 

 other only for a portion of their length, the parts analo- 

 gous to the sternal ribs being simple cartilage, and the sternal pieces partially 

 notched as in the sea-tortoises, not covering the whole lower surface. After 

 death the very rough surface of the ribs may be perceived through the dried 

 skin ; their feet, like those of the fresh water tortoise, are palmated without 

 being lengthened, but only three of their toes are possessed of nails. The 

 horn of their beak is invested externally with fleshy lips, and their nose is 

 prolonged into a little snout. Their tail is very short. They live in fresh 

 water, and the flexible edges of their shell aid them in swimming. 



T. JEgyptiucus, GeofF. (The Tyrse.) This species is sometimes three feet 

 in length, of a green colour spotted with white, its shell but slightly convex. It 

 devours the young crocodiles as soon as they leave the egg, as the following 

 species does the alligators of America, and thus renders important services to 

 Egypt. 



Test.ferox, Gm. (The Soft-shelled Tortoise of America) inhabits the rivers 

 of Carolina, Georgia, the Floridas, and of Guiana. It remains in ambush 

 under roots of reeds, &c., whence it seizes birds, reptiles, &c., devours the 

 young alligators, and is devoured in turn by the old ones. Its flesh is highly 

 esteemed. 



