BY J. DOUGLAS OGILBY. 21 
Length of carapace to 33 feet. 
Distribution as in the genus. 
The food of the edible turtle consists entirely of seaweeds. 
Genus IV., ERETMOCHELYS. 
Eretmochelys, (Fitzinger) Agassiz, Contr. Nat. Hist. U.S., i. p. 380, 
1857 (imbricata). 
Onychochelys, Gray, Proc. Zoél. Soc., 1873, p. 397 (kraussi==imbricata). 
Carapace with persistent fontanelles between the costal 
and marginal plates, its margin serrated posteriorly ; marginal 
shields twenty-five ; four pair of costal shields ; intergular 
shield present, well developed). Head small; jaws hooked ; 
symphysis of lower jaw long; two pairs of prefrontal shields. 
Carnivorous (é€petpos, an oar, XéAvs, a tortoise). 
All tropical and subtropical seas. | Monotypic. 
ERETMOCHELYS IMBRICATA. 
Testudo imbricata, Linnzeus, Syst. Nat., i. p. 350, 1766. 
Chelonia imbricata, Schweigger, Prodr., p. 21, 1814; Dumeéril & 
Bibron, Erpét. Gen., ii. p. 548, pls. ii & xxiii. fig. 2, 1835. 
Eretmochelys imbricata, Agassiz, Contr. Nat. Hist. U.S.,i. p. 381, 1857. 
Chelone imbricata, Boulenger, Catal. Chelon., p. 183, 1889. 
THE HAWKSBILL TURTLE. 
Carapace tricarinate in the young, with the shields strongly 
imbricate, the vertebrals rhomboidal ; dorsal shields of adult 
smooth, of old specimens juxtaposed. Edges of jaws not or 
but feebly denticulated. Limbs with two claws. Carapace 
marbled with yellow and dark brown; posterior yellow ; 
shields of head and limbs dark brown, with yellow borders. 
(imbricata, overlapping; in allusion to the dorsal shields of 
the young). 
Length of carapace to 3 feet. 
The Hawksbill Turtle, from which the so-called tortoise 
shell of commerce is derived, is wholly carnivorous. 
Genus V. CARETTA. 
Caretta, Merrem, Tent., p. 17, 1820 (atra=caretta). 
Thalassochelys, Fitzinger, Ann. Wien. Mus., i. 1835, p. 121; Boulenger, 
Catal. Chelon., p. 184, 1889. 
Caouana, Gray, Catal. Tort., p. 52, 1844 (caretia). 
Carapace completely ossified in the adult, its margin 
formed of twenty-seven, rarely twenty-five shields. Costal 
shields in five or more pairs ; intergular shield very small or 
