16 PYXIS. 



Hab. in Demerara, (v. v. Hort,, D. Bell.) j3 Guadalonpe. 



Peculiar for the upper edge of the fifth vertebral plate 

 being prominent, giving the back of the shell an angular ap- 

 pearance, while in the next the central part is convex. 



2. Kifiixys erosa. ( Eroded Kinixys.) — Testa oblonga fusca, 

 margine posteriore refiexo denticulato, scutello vertebrali 

 5 equaliter convexo, nuchali nullo, (v. Mus. Brit.) 



Junior. Testa dorsi postice rotundata. Kinixys castanea, 

 Bell. Lin. Trans, xvii. t. 18. 



Pullus. Testa depressa dorso immobili, margine denticu- 

 lato. Testudo denticidata, Shaw, Zool. iii. t. 13, (v. Mus. 

 Col. Chir.) et Test, erosa, Schw. (from Shaw.) 



Hab. (v. V. et t. Mus. Brit.) 



When young, the shell is depressed, with a strongly denti- 

 culated margin all round, and the back is not moveable. The 

 shell gradually increases in weight and solidity, and the 

 dorsal suture becomes distinct, but it is not till the adult age 

 that the centre of the fifth -vertebral plate becomes convex, 

 and slightly produced. 



Gen. 4. PYXIS. Bell. (Box Tortoise.) 



Testa dorsi solida, sterni lobus anterior mobilis, sutura 

 inter scutella humeralia et pectoralia. 



The front lobe of the sternum is moveable, like the Box 

 Terrapins (Kinosternon) ; but here the suture is placed be- 

 tween the humeral and pectoral sternal shields, while in those 

 tortoises it is always placed between the pectoral and abdo- 

 minal ones. This shell is distinguished at first sight from 

 the last-named by its greater convexity and solidity. The 

 sternum has also twelve plates, while the other box tortoises 

 have either eleven [Kinosternon) or thirteen [Sternotherus.) 

 The feet are clavate, hke those of the other animals of this 

 family. 



1 . Pyxis aranoides, [Radiated lax tortoise.) — Testa hemis- 

 pherica, luteo nigroque variegata. 



Pyxis aranoides, Bell, Lin. Trans, xv. t. 16. 



Hab. (v. t. Mus. D. Bell.) 



Length six, breadth" four inches ; varies greatly in the in- 

 tensity of its colour in the three specimens which are in Mr. 

 Bell's collection. 



