46 



REPTILES. 



Fam. IV. Soft Turtles, (TrionycidjE). 



Head flattened, ovate: eyes small, superior: jaws horny, co- 

 vered with dependant fleshy lips: chin not bearded : nostrils elon- 

 gated into a thin cylindrical trunk. Neck long, contractile. Feet 

 short, strong. Toes 5-5, short, expanded, strongly webbed, two 

 outer clawless : claws 3-3. Tail short, conical, simple. Shell co- 

 vered with a hard cartilaginous skin, usually expanded and flex- 

 ible on the edge, the ribs only united together and to the vertebrae 

 above, separate below. Sternum formed of a ring of bones, cover- 

 ed with a continuous skin, and in the adults furnished with rough 

 callosities on the prominent part. Pelvis only attached to the ver- 

 tebrae. Living in rivers and lakes in warm climates, eating flesh, 

 and rarely vegetables. Eggs spherical. 



The ribs become united together for a greater length, and the 

 sternal callosities appear and increase in size as the animal in- 

 creases in age, hence they do not afford specific, much less gene- 

 ric characters. 



Synopsis of the Genera. 



A. Sternum broad, with valves over the feet. The margin of the 



shield supported by bones. 



1. Emyda. Head moderate, sternal callosities 5. 



B. Sternum narrow at each end. The margin of the shield expand- 



ed, flexible, thin. Sternal callosities 4. 



2. Tyrse. Head moderate, ovate, narrow in front: lips thin. 



Ribs 8 pair, forming a disk with the vertebra? when young. 



3. Doganu. Head very large, dilated behind, narrow in front: 

 lips thin. Ribs 8 pair, not united in a solid disk until late in 

 life. 



4. Chitra. Head dilated behind, broad and short in front : lips 



very large, swollen. Ribs 8 pair. 



5. Trionyx. Head moderate, ovate, narrow in front. Ribs 

 7 pair. 



1. Emyda, Gray. Cryptopus, Dum. et Bib. 



Head moderate, ovate, narrow in front. Lips thin. Margin 

 of the shell supported with a series of bones. Sternum broad, 

 rounded before and behind, with a moveable valve over each foot. 

 Sternal callosities (of adult) 5. 



The Bungoma. Emyda punctata, Gray, Syn. Rept. 50. ///. 

 hid. Zool. ii. t. 62, young. Bell, Testud. t. Testudo punctata, 

 Lacep. t. 7.f. 1. Test, granosa, Schoepf. Test. 127, t. 30, A, B. 



