Sir H. H. Howorth — The Baltic — The Ancylm Sea. 339 



and, at Ponal and Pallifer, at a distance of 20 versts from the 

 water. Further inland, he adds, no such marine shells occur, but 

 only fresh- water shells such as Ancylus fluviatilis and pieces of JJnios. 



On the mainland he found the same deposit with Ancylus fluviatilis 

 at Mannalas at a considerable elevation, at Padis in gravel, and 

 mixed with Paludina baltica near the church of Karusen. In some 

 places the latter shell occurs alone. He remarks that hitherto 

 Ancylus fluviatilis had not been found in the sea and only in running 

 streams. Its near relative Ancylus Baicalensis is found in Lake 

 Baikal with certain marine Crustaceans, pointing to the former union 

 of that great lake with the Polar sea. The two shells above named 

 also occur in the gravel mounds on the top of the island of Mohn 

 (op. cit., pp. 55, 5G). 



In 1881 Geikie published his work "Prehistoric Europe," in 

 which he has a paragraph about these fresh-water beds which is 

 interesting as showing that the problem had then been considerably 

 illustrated by Krapotkin and Schmidt, although he unfortunately 

 (as Munthe also complains) does not give a reference to the memoir 

 where their researches were published, and which I cannot trace. 

 They argued, according to Geikie, that in Finland the fresh-water 

 beds were older than the marine ones, and that the Gulfs of 

 Bothnia and Finland existed at the end of the Glacial period as 

 great fresh-water lakes, and they quote the terraces which mark 

 their ancient margins as being found there, as they are on certain 

 islands of the Baltic, such as Mohn and Dago. Similar terraces at 

 higher levels have been traced in the interior of Finland up to 150 feet. 

 " The whole region .... seems to have been covered, over 

 wide regions, with extensive sheets of fresh water. In many cases 

 the natural dams which held in their waters consisted of dsar or 

 great gravel ridges that were rendered watertight by the mantle of 

 loam and silty clay which often cloaks their slopes. The different 

 levels of the ancient lakes as their confining barriers gave way 

 are marked by terraces eroded in the sides of the dsar. It is 

 remarkable that .... not a single sea-shell has yet been 

 detected in the interior of Finland " (Geikie, op. cit., p. 470). 



In 1884 Schmidt published a memoir in the Zeitsch. der Geol. 

 Gesellsch. on the Glacial and post-Glacial deposits of Esthland, Oesel, 

 and Ingermanland, in which he added some further facts to those here 

 stated. He there tells us that the fresh- water shells occurring in the 

 beaches consist in the main of Ancylus fluviatilis and Limncea ovata, 

 but there are also found Unio, Cyclas, Paludina impura, and 

 Neritina fluviatilis var. In Oesel these beaches occur near Arensburg 

 from a height of 20 feet up to 100 feet in the higher parts of 

 the island. In Mohn they occur in the highest part of the island, 

 near the church ; while on the mainland our author reports them 

 from Karusen, St. Michaelis, Fickel (Awaste), Piersal, Mannalas, 

 Kegel, Hirro near Keval, and further east below the Jaggowalschen 

 waterfall. Still further east the same beds, but without shells, 

 occur at Kuckers, Sackhof, etc. 



Schmidt in describing these deposits confesses himself unable to say 



