260 LEAVES FROM THE 



which, Wiien closed, the head and fore-feet are closely 

 boxed lip, it lowers the lid, protrudes its head and fore- 

 feet, and walks or feeds till danger approaches, when 

 it draws them in, raises the lid, and thus shuts itself up 

 in a compact box ; for the edges of this operculum on 

 hinges fit close as wax to those of the carapace, which here 

 forms a sort of animated dooT-case. Thus the animal 

 has nothing to fear in front ; and behind, it is securely 

 protected by its enlarged and deepened plastron, under 

 which the posterior extremities and tail can be entirely 

 and snugly drawn up. Among the marsh-tortoises * 

 there is a similar conformation ; and the species so pro- 

 tected have obtained the apt name of box-tortoises. 



But, as if Nature were determined to show that she 

 can vary any plan, however ingenious, she has thought 

 fit to turn out of hand another phase of this box-like 

 construction, and in Kinyxis we have it behind instead 

 of before. The tortoises of this group are gifted with 

 the power of moving the posterior part of their carapace, 

 which they can lower and apply to their plastron, so as 

 completely to close the box behind, as those of the 

 genus Pyxis close the anterior part of their shells. But 

 in Kinyxis there is no hinge-like apparatus as there is 

 in Pyxis. In Kinyxis the bones bend ; and, in conse- 

 quence of their thinness and elasticity, the carapace can 

 be bent down at the will of the animal, so as to approxi- 

 mate the plastron. A sinuous line, on which the animal 

 mechanism operates, is indicated externally between the 

 penultimate and ante-penultimate marginal plate; and 

 this point, or, rather, line of flexion, is furnished with a 

 tissue partaking of the nature of fibre and cartilage. 



But which of the land-tortoises furnished the shell — 

 the chorded shell, dear to Apollo and the Muses ? 



Pausanias says, that it was a species which was found 



* Sternothccrus. 



