TESTUDINATA. 461 



half way to the beach, a fore and hind flipper chopped off by the 

 sharks, and it was supposed that it had remained ashore to keep out 

 of their way. A fourth specimen, found in the same situation, had a 

 hole bitten out of its side. They were frequently seen swimming from 

 the boats, and probably numbers might have been taken by remaining 

 a night on the island. There is here no vegetable food for them, un- 

 less the plants on shore, which did not appear to be cropped." 



Log. — Honden Island, Paumotu Group ; Tahiti and Eimeo ; Rosa 

 Island. 



Plate XXXI, fig. 8, represents an outline, seen from above, of the 

 carapax of Chehnia tenuis^ considerably reduced in size. 



Sub-Ordo II. TESTUDINATA. 



The representatives of this group inhabit either dry land, marshy 

 districts, or fresh waters. Their body is generally depressed, broader 

 than deep, rounded, elliptical, or ovate in its outline, which is either 

 even, or variously serrated or emarginated, and covered with epidermic 

 or horny scales, or a soft skin. The plastron is broad, or narrow; im- 

 movable, or movable either upon its anterior or posterior half, or both 

 ways at the same time. There are four limbs, an anterior and a poste- 

 rior pair, subequal, moderate in length, slender or stout, and more or 

 less retractile. The hands and feet are club-shaped, palmated, or semi- 

 palmated, the fingers and toes being always movable, terminated in 

 part or in totality by blunt nails or acerated claws, which vary from 

 three to five. The tail is conical, tapering, long or short. 



The head is subquadrangular or subcircular across the orbits, pro- 

 tected with plates, or covered with a naked skin; the snout being 

 pointed or abbreviated. The neck is retractile or simply contractile ; 

 generally naked, exhibiting sometimes membranous flaps or appen- 

 dages, and occasionally covered with scales. The eyes, as a general 

 feature, are large, and in a few instances, quite small, compared to the 

 size of the animal. The nostrils are anterior, quite approximated. 



The food of the Testudinata consists of animal and vegetable sub- 

 stances, according to the genera and species. 



116 



