TESTUDO. 



13. Trionyx. — Sternum angustum. 



14. Emyda. — Sternum latum, lateribus valvis munitum. 



Fam. V. CHELONiADiE. — Pedes pinniformes, compressi. 



15. Sphargis — Testa cute coriacea tecta. 



1 6. Chelonia. — Testa scutellis tecta. 



Fam. 1. TESTUDINID^. 



Pedes clavati, ungues 5-4 obtusi, maxillae cornese. Testa 

 solidissima scutis corneis tecta, scutellis marginalibus 24, 

 caudali lato inflexo. 



The head is globular, shielded ; the jaws are covered with 

 horny sheaths ; the neck is thick and retractile. The shell 

 is more or less globular, very solid and thick, the ribs being 

 united together quite to the margin when the animals are 

 adult, and covered with horny shields, which are generally 

 grooved, and exhibit their areola for a considerable time. 

 The sternum is broad and very solid, the bones of which it 

 is formed filling up the centre ; and it is firmly attached 

 to the upper shell by a bony suture as long as the abdo- 

 minal and pectoral plates. The marginal plates are 24 or 

 26 in number, and have often a nuchal one in front ; the 

 hinder pair are always united together, and form a single 

 broad incurved plate. The feet are short and clubbed, very 

 like those of an elephant in shape, and armed with short 

 blunt claws. The tail is thick and short. They are slow in 

 their motions, eating vegetables and roots, and living in 

 woods or fields in warm parts of the world. In a cold cli- 

 mate, they burrow and sleep during the winter. 



Gen. 1. TESTUDO. (Tortoise.j 



Scutum dorsale sternaleque solida, scutella sterni 12, 

 gulana distincta. 



The sternum. of this genus is generally quite solid and des- 

 titute of any movement, but Mr. Bell has informed me that 

 he has observed in the female of T. Grceca and T. areola, 

 that just before they are about to deposit their eggs, the hinder 

 lobe of the sternum becomes loosened and capable of a 

 slight mobility. 



