CIIELONIID^. — CXVIII. 205 



Family CXVITI. CHELONIID^. (Logger-head 

 Turtles.) 

 Sea turtles, with the carapace covered with bony plates ; carapace 

 heart-shaped, broad and flat, highest in front, widest near middle ; 

 head large, jaws without tooth-like projections. Genera 4 ; species 

 about 7, of the open sea, coming to shore only to dejiosit and burv 

 their eggs. 



a. Scales around large median plate on top of head 13 to 20; plates of carapace 

 not imbricate; edge of lower jaw not serrate; costal plates 5 on each side; 

 scales on ciieeks small, 15 to 20; head broad. . Thalassochelys, 3U2. 

 aa. Scales around vertical plate 7; costal plates 4. 



b. Tomia of lower jaw not serrate; shields of carapace imbricated; scales on 



cheeks large, 7 to 10; head broad Eretsiochelys, 30-3. 



bb. Toniia of lower jaw serrate; shields of carapace not imbricated; scales 

 on cheeks small, 15 to 20; head high and narrow. . Chelonia, 304. 



302. THALASSOCHELYS Fitzinger. (^aXao-o-u, sea ; 

 X^^vi, tortoise.) 



^, 596. T. caretta (L.). Logger-head Turtle. Scales not 

 imbricate ; 2 nails to,each foot. Atlantic, N. to Mass. ; reaches 

 450 lbs. (^Eu.) (An old name.) 



303. ERETMOCHELYS Fitzinger. (eperfiis, oar ; x^'^^s.) 



597. E. imbricata (L.). Tortoise-shell Turtle. Hawks- 

 bill Turtle. Jaws produced in a beak ; nails two. N. C. to 

 Brazil. Smaller and fiercer than the preceding, its scales used in 

 making combs. 



304. CHELONIA Brongniart. (xe'S.avTj, tortoise.) 



598. C. mydas (L.). Green Turtle. Plates thin ; nail sin 

 gle ; body oblong. L. I. to Brazil, herbivorous, reaching 850 lbs., 

 and valued as food. (/uiuSacu, to be wet.) 



Family CXIX. TRIONYCHID^. (The Soft-shelled 

 Turtles.) 



Body flat, nearly orbicular ; carapace not completely ossified, the 

 ribs projecting freely towards the outer extremities ; marginal ossi- 

 cles rudimentary • carapace and jilastron covered by a thick leathery 

 skin which is flexible at the margins. Head long and pointed, with 

 a long, flexible, tubular, pig-like snout ; neck long. Feet broadly 

 •webbed ; toes long, 5-5, but the claws only 3-3. 



Aquatic, carnivorous and voracious ; species about 30, in both 

 hemispheres. 



a. Nostrils rather under the tip of snout; nasal septum without an internal 

 longitudinal ridge on each side; head narrow; edge of upper jaw serrate 

 behind Amyda, 305. 



