311 



furnished the fossil remains of this genus in the plaster 

 quarries of Montmartre. It should be remembered, that 

 the ribs in this subgenus do not have the spaces between 

 their ribs ossified in their whole length ; that their ribs do 

 not articulate at their outer ends with the bony margin ; 

 and that their surface is always shagreened or grooved 

 with an infinity of little irregular pits, by which the soft 

 skin, the only tegument with which the carapace, in this 

 subgenus, is covered, is rendered more adherent. The 

 trionyx is not known to live in any other situation but in 

 fresh water. 



There appear, besides these, to be the remains of two 

 species of fresh-water tortoises, emydes : and no fossil 

 remains of sea-tortoises have been discovered in these 

 quarries. 



In the neighbourhood of Verona, and chiefly in the 

 valley of Ronca, a formation, the fossil remains of tortoises 

 are also found, but in fragments too small to yield any 

 characteristic marks of the species to which they belong. 



Solipedes. — The horse : the fossil teeth of horses have 

 long been described by different authors ; and have some- 

 times been attributed to giants, hippopotami, «&c. but, 

 although they have been found in a state of petrifaction, 

 and in the same caverns with the remains of tigers, rhinoce- 

 roses, and hyaenas, and even in the same deposits with 

 unknown animals, there are no anatomical differences dis- 

 coverable in the skeletons of the fossil animals which will 

 distinguish them from those which are found in alluvial 

 deposits, or from those of horses which are now existing. 



The remains of this animal are frequently found in peat 

 beds, and in alluvial depositions. I do not know of any 

 instance of their being found imbedded in a lapideous mass. 



The ox, or the buffalo, are the animals with which the 

 remains of the horse are most likely to be confounded; to 



