8 EMYDOSAURIAN AND TESTUDINIAN REPTILES 
SUBORDER I. ATHEC. 
Vertebre and ribs free, separated from a bony exo- 
skeleton. Skull without descending processes of the parietal 
bones. —Boulenger—(a, priv. ; @yxyn, a box.) 
Family A. SPHARGIDID.* 
THe LEATHERY TURTLES. 
Shell without epidermal shields, the exoskeleton consist- 
ing of numerous small bony plates arranged like mosaic. 
Limbs paddle-shaped and clawless, the phalanges without 
condyles. Marine. 
Monotypic. 
Genus 1. DERMOCHELYS. 
Dermochelys, Blainville, Journ. Phys., Ixxxiii. 1816, p. 259 (cortacea) ; 
Boulenger, Catal. Chelon., p. 7, 1889. 
Sphargis, Merrem, Tent., p. 19, 1829 (mercurialis=cortacea). 
Dorsal shield completely, ventral incompletely ossified 
in the adult, the former with seven, the latter with five keels. 
Head covered with smal] shields. Upper jaw anteriorly with 
two triangular cusps situated between three deep notches ; 
lower jaw with a single cusp, which fits in between the upper 
pair, when the mouth is closed.  (d€pya, skin; xXéAus, a 
tortoise.) 
All tropical seas. 
1. DERMOCHELYS CORIACEA. | 
Testudo coriacea, Linneus, Syst. Nat., i. p. 350. 1766. 
Sphargis coriacea, Gray, Synops. Rept., i. p. 51, 1731: McCoy, Prodr. 
Zool. Vict., ii. dec. 11, pl. ci, 1885. 
Dermochelys coriacea, Boulenger, Catal. Chelon., p. 10, 1889. 
THE LOUTH. 
Carapace broad in front, acutely pointed behind. Fore 
limbs narrow and falcate, as long as the dorsal shield in the 
young, shorter in the adult ; hind limbs short and truncated. 
Dark brown to purplish black above, uniform or spotted with 
yellow ; under surface of limbs and sometimes of throat 
pinkish or yellowish. (coriacea, leathery.) 
*The Century Dictionary derives the generic name Sphargis from the 
latin Sphargis (gen. Sphargidis) ; if this be correct the family name should 
be Sphargidide. The word, however, is constructed more on a Greek than 
a Latin model, but no such word occurs in the dictionaries of either language 
to which I have access. 
