252 H. H. Hoicorth — The Mammoth in Europe. 



one, namely, Limnea minuta, is fluviatile, and of this only 28 indi- 

 viduals out of 200,000 specimens have been noted. The greater 

 part of these species, says our author, still live in the country ; the 

 rest are so little different that they may be treated as mere varieties. 

 Nearly all still live in cold damp clhuates, and some in the Alps as 

 high as the limits of snow (Bull. Geol. Soc. of France. voL xxiv. 

 p. 490). 



Heer, speaking of the same class of shells, refers to the twenty- 

 one sjDecies found by Professor Mousson in the Gallen part of the 

 Ehine Valley, and described by him in the Transactions of the 

 Natural History Society of Zurich in 1856, says they still without 

 exception occur in Eastern Switzerland, most of them in the valley 

 of the Rhine or at the foot of the nearest mountain slopes. Helix 

 ruderata is not now found in the plain, however, and only in the 

 highest mountain region, that of the mountains of Glaris, Prattigau 

 and the Senlis chain. Helix sericea glabella and Helix arhustorum 

 subdlpina also belong to the mountain region. Helix strigella, with 

 a wide umbilicus, still occurs near Sargans, and is peculiar to that 

 district. All the species except the four first named, says Heer, are 

 either forest snails from the region of leafy trees, or species which 

 prefer shady moist places. Inhabitants of dry sunny localities are 

 wanting. . . . Speaking of the Loess of the Lower Rhine, he says of 

 the numerous snails which have been collected in it, the species of 

 shady moist localities certainly predominate, and with them are 

 mixed certain forms (such as Helix hispida, Helix ruderata, and 

 Helix arhustorum suhalpina), which at present are met with only in 

 high mountains, while no species occur which belong to warm sunny 

 localities (Pi-im. World of Switzerland, vol. i. pp. 213 and 214), 



M. Tournouer, in describing the similar raollusca from the tiiffs of 

 IMoret in the valley of the Seine, says that thirty-five species in all 

 were discovered. They must have lived in the recesses of moist 

 woods attached to leaves, to tender herbaceous plants, and to rocks 

 where water fell ; some wei"e probably brought down fi'om a higher 

 level by torrents. Of the thirty-five species just named, one half 

 still live in the neighbourhood ; of the rest, some, like the Helix 

 limbata, belong to the sub-Pyrenean district of South-western France, 

 others to the mountain districts of the AIjds and Jura. Of this 

 class are Bidimus montanus, Clausilia dubia, Pomatia septem- spiralis, 

 etc. ; some to Eastern Europe, as Helix hidens, Clausilia piimila, etc. ; 

 others again to Southern forms, as Vitrina major, Zonites acies, a 

 Helix, like Helix fridicum, etc. Some kinds seem to be extinct, as 

 Succinea Joinvillensis, Gyclostoma lutetianum, several forms of Succinea, 

 Zonites, and Clausilia. The most common species at Moret are the 

 Helix arhustorum and nemoralis, still found over all Central and 

 Northern Europe. The whole class found here is singularly like 

 the parallel class from Canstadt, in Wurtemberg, both deposits 

 being marked by the peculiar forms Helix hidens and Zonites acies. 

 They bespeak a diffusion of European species more uniform than 

 prevails now, with a damp and more uniform climate than now 

 prevails, and at Moret one with a somewhat higher mean tempera- 



