GEOLOGY. 



181 



Fresh Water Formation. 



Gypsous marl and silicious calx, composed of beds of marl 

 with Lymnese and of a compact calx with a fine grain impreg- 

 nated with silex, in the midst of which are interspersed ovoid 

 masses of gypsum containing numerous bones of terrestrial 

 Mammalia (Palseotherum, Anoplotherum). The shells in- 

 cluded in gypsous marl are particularly those called Lymnese, 

 Cyclostomes, Planorbes and other fluviatile Mollusca. The 

 Palceothera, are Pachydermata intermediate between the Tapir 

 and the Rhinoceros ; bone of the nose very short, and seem- 

 ing to require a little proboscis ; six incisors and two canines 

 in each jaw ; feet divided into three toes ; seven species are 

 found in the lime-pits in the vicinity of Paris, of which the 

 greater portion are about the size of a Horse, the rest of a 

 Hog, Sheep or Hare. The Anoplothera are Pachydermata 

 remarkable on account of teeth in a continued series, as we 

 find in the Bimana family, contiguous and without interval, 

 and on account of an unique organization of a cloven foot 

 where the metatarsian and metacarpian bones are not united 

 in a cannon. The best known species of these animals, which 

 are peculiar to the lime-pits and coarse calx in the vicinity of 

 Paris, resembled a large Otter, and frequented lakes, in the 

 bottom of which its bones are found incrusted in gypsum. 



Superior Tertiary Earth. 

 Marine Formation. 



Sands and marine freestone of Fontainebleau ; sands strati- 

 fied in distinct beds, ferruginous and micaceous ; very hard 

 banks of freestone with marine shells in the superior portions 

 of the deposit. 



Fresh- Water Formation. 



Superior fresh-water calx and mill-stone. Mill-stone is the 

 name given to a silex indented with a multitude of irregular 

 cavities, supplied with silicious filaments arranged much like 

 the reticulated tissue of bones, and spread with an ochrous 

 plaster; these cavities are often filled with clayey marl or 

 sand, and have no communication. 



