Mr. Bell on two new Genera of Land Tortoises. 395 



to my former theory. The possession at length of a specimen 

 of the same species, in which the sternum was uninjured, con- 

 firmed its truth, however, by exhibiting a perfect land Tortoise 

 with the anterior lobe of the sternum moveable, and capable of 

 as accurately closing the shell, as in any species of the fresh- 

 water Box Tortoises. 



This peculiarity, so unexpected in the Land Tortoises, ap- 

 pears to be sufficiently important, connected as it is with a 

 remarkable modification of the muscular system, to require a 

 distinct generic appellation, which I propose to supply by the 

 name Pyxis. 



The importance of such species as form a passage from one 

 group to another, and the affinities of Avhich serve to indicate 

 the relations whereby the different groups are connected, will 

 perhaps be a sufficient excuse for my having dwelt so long on 

 the minute circumstances connected with the history of those 

 species which form the subject of this paper ; especially when it 

 is considered, that in the present instance they fill up a hiatus 

 which has long interfered with a perfect knowledge of the na- 

 tural arrangement of the order. 



'&^ 



Ordo. Testudinata, Merrem. 

 Fam. Testttdinid^. 



Genus. PYXIS. 

 Pedes clavati ? 



Testa gibba. 



Sterni lobus anterior mobilis, ligamento articulatus. 



Pyxis arachnoïdes. Tab. XVI. Fig. 1. 2. 



Habitat ? 



Mus. nostr. 



De- 



