352 Sir H. H. Hoivorth—The Baltic— The Ancylus Sea. 



Bothnia to have only one-fourth of the saltness belonging to 

 the ocean. 



" I cannot doubt that these large erratics of Upsala were brought 

 into their present position during the recent period .... 

 The Upsala erratics may belong to nearly the same era as the refuse 

 heaps (i.e. the Danish kitchen middens)." ("Antiquity of Man," 

 pp. 281-2.) 



This is a remarkable conclusion for a man of Lyell's views to 

 have arrived at, and it clearly shows that in his view the asar, or 

 some of them, actually dated from so recent a time as the Neolithic 

 age, when the climate of Northern Europe was milder than it is now, 

 and when ice-portage, as necessitated by the glacialists' theories 

 about these and similar erratics, are quite out of court. 



I quote it as showing that Lyell had no hesitation in attributing 

 the formation of the Jisar and the distribution of the enormous 

 erratics which crowd their backs to the action of water, and not to 

 that of ice, a fact for which I have made a vigorous fight in my 

 work recently published. It seems to me, however, that the water we 

 must appeal to in such a case is not the sea in its normal moods, but 

 the sea when under the influence of some cataclysmic impulse such 

 as I have shown to have probably initiated the Litorina stage of the 

 history of the Baltic. If this is to be appealed to as the fashioner 

 of the asar it may be that we have been too sanguine in treating all 

 the more recent raised shell-beds in the Baltic area as measures and 

 indices of the former permanent level of the sea, and that they may 

 rather mark the level at which the huge tide caused by the breach 

 in the old land-bridge deposited its load of debris. I may revert to 

 this issue in another paper. 



EXPLANATION OF PLATE XIX. 

 I. 



Map of the Baltic as it is now aud as it was at the maximum limit of the Litorina 

 Sea. After De Geer. Nathorst, Sveriges Geologie, p. 267. 



II. 

 Fig. 1. Cardium edule (dwarfed form) from Gotland. 

 ,, 2. Cardium edule (normal growth, natural size) from the Cattegat. 

 ,, 3. jTe/^iwa ia^^Aim (dwarfed form) from the as at Enkoping. 

 ,, 4. Litorina litorca (dwarfed form) ,, ,, 



,, 5. Litorina litorea (normal growth, natural size) from the Cattegat. 

 ,, 6. Paludinclla balthica (dwarfed form) from Gotland. 

 (See Nathorst, Sveriges Geologie, p. 270.) 

 Figs. 2 and 5 give the normal growth of Cardium and Litorina and their natural 

 size at the Cattegat, where they enjoy the full amount of salt water. Figs. 1 and 4 

 show the same species of shells from Gotland and Enkbping, dwarfed by the decreased 

 salinity of the waters as one recedes from the ocean towards the inner recesses of the 

 Baltic. The Tellina, Fig. 3, is a similarly dwarfed variety ; but Fig. 6, Faludinella, 

 a fresh or brackish water shell, owes its degeneracy to too saiine conditions. 



Ereata in the previous Paper. 



Page 311, line 8; 317, 1. 42; 318, 1. 38; and 320, 1. 9,/o)- De Geers read De Geer. 



Page 314, 1. 29, after balthica, insert Scrohicnlaria piper ata. 



Page 318, 1. 10, for which read what ; and 1. 17, for wash read mark. 



Page 319, lines 1 and 16, for Lomberg read Lonnberg ; and 1. 40, for has read have. 



