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



Species and Varieties of Shells characteristic of the 

 YoLDiA Clays. 



NepUmea despecta, var. carinata. 



N. denselirata, n.sp. 



Sipho togatus, var. Pfaffii, var, 



sinuosa, var. vallensis. 

 S. brevispira. 

 S. islandicus. 



S. Verkrutseni, var. plicifera. 

 TropJion truncatus, var. major. 

 Cylichna Reinhardti. 

 Modiolaria nigra. 

 Portlandia arctica = Yoldia 



arctica, var. siliqua, var. 



portlandica, var. inflata, var, 

 Yoldia hyperborea. 

 Admete viridnla. 

 Beta nobilis, var. rugulata. 



Of these species and their varieties 26 have been found at 

 Glomraen between Sarpsborg and Frederikstad, 1 1 at Sandefjord, 

 8 at Tonsbeig, and 9 at Moss. 



From the Yoldia clay at the last named of these places Brogger 

 also enumerates a number of Forarainifera, and among them he 

 characterizes Polystomella arctica as being a high Arctic species 

 (op. cit., 33 and 670). 



I will now give the living habitat of some of the above shells : — 



Macoma calcarea. The coasts of North Siberia and North America, 



Greenland, and Spitzbergen. 

 Saxicava arctica. The Kara Sea and North Siberian coast and West and 



North Greenland. 

 Pecten islandicus. Greenland and Finmark. 



Leda pernula, var. costigera. North Siberian coast and Greenland. 

 Nucula tenids. North Siberia coast, Spitzbergen, Melville Bay, and 



Greenland. 

 Lyonsia arenosa. Nova Zembla and West Greenland. 

 Lepeta cocca. Greenland and Grinnell Land. 

 Natica affinis. The Kara Sea and generally eircumpolar. 

 Lunatia Groenlandica. North coast of Asia, Greenland, and generally 



eircumpolar. 

 Astarte undata. Kara Sea, north coast of Asia, Spitzbergen, and 



Greenland. 

 Buccinum terra-novce. Nova Zembla, North Siberian coast, the islands 



of the St. Lawrence, and Greenland. . 



B. hydrophanum. East Greenland and Spitzbergen. 

 Neptunea despecta. Finmark, Nova Zembla, and north coast of Asia. 

 Sipho togatus. Kara Sea, north coast of Asia, and Spitzbergen. 

 S. islandicus. Nova Zembla, north coast of Siberia, Gulf of St. Lawrence, 



Spitzbergen, and Greenland. 

 Trophon truncatus. North coast of Siberia and Greenland. 

 Cylichna Reinhardti. Nova Zembla and north coast of Asia. 

 Modiolaria arctica. Finmark. 

 Portlandia arctica. Nova Zembla, the Yenissei, Franz Joseph Land, and 



Greenland. 

 Yoldia hyperborea. Greenland, Spitzbergen, and Finmark. 



