62 



calcarea, Pecten Islandlcus ; on the other hand, I collected 

 species here of which I did not find any representatives at 

 Kapellbackar, viz. : Odrea edidis, Luclna horealis, Cardium 

 edule, and Nassa reticulata, with these were Trophon 

 clathratus, which Dr. Gwyn Jeffrej^s describes as a high 

 northern species, and found living only within the arctic 

 circle. 



Dr. Jeffreys records from this deposit some species which 

 I did not meet with there, viz. : Tapes pullastra, Corhula 

 gibha, and Aporrhais pes-pelecani, which he says, with the 

 Ostrea edulis, " are shells of rather a southern type." Now 

 one of these species, Aporrhais pes-pelecani, which Dr. 

 Jeffreys considered absent from Kapellbackar, I was success- 

 ful in finding there. 



This mixing up of species of a southern type with those 

 of an undoubted arctic or boreal type, is somewhat difficult 

 of explanation. Some of these apparent anomalies may be 

 ascribed to our ignorance of the extent of the range of some 

 of these moUusks in our present seas, or this influx of 

 southern types may be due to changes in the sea bed, 

 currents of warmer water finding their way northwards, 

 bringing with them denizens of a more southern latitude. 



Whatever may be the interpretation of these difficulties, 

 we may be certain that these immense heaps of fossil shells 

 are the result of slow growth and accumulation, during 

 which many changes of elevation and depression of the coast 

 line have taken place. 



That these shells indicate colder climatal conditions than 

 those now prevailing on the coasts of Southern Sweden, is 

 proved by the absence of the large Pecten Islandlcus from 

 the neighbouring sea, and most of them are at present in- 

 habitants of the Arctic Ocean, and have been dredged from 

 the Greenland and Spitzbergen waters. 



Many of them are also common shells in our glacial clays 



