50 SPHAEGIDJE. 



46. Thalassochelys caretta. 



Testudo caretta, Linn. Syst. Xat. i, p. 351. 



Chelonia caouanna, SeJttDeigg. Prodr. p. 22. 



Chelonia olivacea, Eschsch. Zool. Ail. p. 3, pi. iii ; Cantor, J. A. S. B. 



xvi, 1847, p. 619. 



Caouana olivacea, Giinth. Rept. B. I. p. 52 ; Theob. Cat. p. 33. 

 Thalassochelys caretta, Bouleng. Cat. Chel. $c. p. 184. 



Carapace of young with three strong keels, of adult arched or 

 subtectiform ; dorsal shields juxtaposed ; margin serrated pos- 

 teriorly in the young, formed of 27, or rarely 25 shields. Intergular 

 shield very small or absent. Head large, with very strong, hooked 

 jaws ; symphysis of lower jaw very long ; alveolar surface of horny 

 beak with a median ridge, of jaws without ; two pairs of shields 

 anterior to the azygous frontal. Limbs of young usually with two 

 claws, of adult frequently with but one. Young uniform dark 

 brown or blackish ; adult brown above, yellowish inferiorly. 



Length of shell 4 feet. 



Hob. Tropical and subtropical seas ; Mediterranean ; an acci- 

 dental visitor in the North. Not rare in the Bay of Bengal. 

 Carnivorous, feeding chiefly ou crustaceans and niollusca. 



Suborder II. ATHEC^E. 

 Family V. SPHARGLD^E. 



Exoskeleton consisting of mosaic-like juxtaposed plates. Plastral 

 elements eight ; no entoplastroii. Limbs paddle-shaped, clawless, 

 the digits of the fore limb much elongate ; phalanges without 

 condyles. 



This family contains a single genus and species, the well-known 

 Leathery Turtle. 



Genus DERMOCHELYS, 



Blainville, Journ. de Phys. Ixxxiii, 1816, p. 259. 



Dorsal shield completely, ventral shield incompletely bony in the 

 adult, the former with seven, the latter with five keels. Beak with 

 two triangular cusps, between three deep notches ; no enlarged 

 alveolar surface, the jaws simply sharp-edged. Head covered with 

 small shields. 



47. Dermochelys coriacea. 



Testudo coriacea, Linn. Syst. Nat, i, p. 350. 



Sphargis coriacea, Gray, Syn. Rept. i, p. 51. 



Dermatochelys coriacea, Giinth. Rept. B.I. p . 55 ; Theob. Cat. p. 34. 



Dermochelvs coriacea. Boulenq. Cat. Chel. <yc. p. 10- 



Tore limbs as long as the dorsal shield in the young, shorter in 

 the adult. Colour dark brown, uniform or spotted with yellow ; 



