404 Sir H. H. Howorth — Geological History of the Baltic. 



Pecten varius. Cochlodesnia prcetenue. 



Saxicava rugosa: Tapes puUastra. 



S. arctica. Venus striahda. 



Tellina proxinia. V. ovata. 



T. solidula. Scrohiciilaria piper ata. 



T. fibula. Ostrea edulis. 



Syndosmya alha. Anomia patelUformis . 



S. intermedia. A. aculeatuvi. 



S. nitida. A. ephippium. - 



Astarte arctica. ■ — — 



A. elUptica. Bhynchonella psittacea. 



A. sulcata. • 



A. compressa. Echinus droehackiensis. 



Thracia villosiuscula. ■ — 



Mactra subtruncata. Balanus porcatus. 



M. elliptica. B. crenatus. 

 See Geol. Mag., 1897, pp. 355, 361; 1898, pp. 195, 257; 1905, 

 pp. 407, 454. 



Others who have devoted some time to the exploration of the later 

 geology of Western Sweden have described the shell beds on its 

 shores, which point the same moral as those of Denmark, namely, 

 their occurrence at a gradually increased elevation as we proceed 

 northwards. In Southern Bohuslan Olbers found the shell beds at 

 a height of 15 metres. At Stromstad De Geer found them at a height 

 of 40 metres, while at Bullaresjon, on the Norwegian frontier, 

 Olbers again records having found them at 48 metres high (Nathorst, 

 Sverige Geol., p. 275). (See Olbers, Bidrag till Gbtelorgs och Bohuslans 

 geologi, Stockholm, 1870; see also on Halland, G.F.F., 1875.) 



Olbers separates the deposits into two series : one of them he calls 

 Cardium lera, characterized by Cardium ediile and C. echinatum, 

 Cyprina islmidica, and Turritella communis, while the other, which he 

 calls Ostrea lera, and which he considers to be the younger, is 

 marked by the presence of Ostrea edulis, with Patella, Cerithitim, 

 Rissoa, etc. There are, however, local variations, due not to 

 difference of age, but of the level at which they lived, and the 

 differing habitat. 



North of Bohuslan we reach the Gotha, a famous river, the gateway 

 of a very interesting portion of Sweden, and specially noteworthy in 

 view of the issues we are discussing. In an earlier page we had 

 a good deal to say of the collapse that occurred in the lowest part of 

 the synclinal depressions through which the Forchhammer line runs. 

 We have now reached the part of Sweden through which another 

 line and focus of movement runs, namely, the highest part of the 

 anticlinal, and therefore also a district in which the tension must 

 have been extreme and the likelihood of great dislocation very great.- 

 The Gotha Hiver, in fact, leads us into a part of Sweden where the 

 proofs of tliis are written on all sides. The Gotha itself now flows 

 through the most tremendous gorges in Europe, the famous 

 TroUhatten falls, which must have been caused' by great breakages. 

 They have all the appearance of being very recent and do not 

 represent in any way the original drainage channel of the river. 

 One fact suggesting a catastrophic cause for them is notable. The 

 salmon which inhabit the great lakes which the Gotha drains must 



