﻿688 SUMMARY OF THE CONTENTS. 



studied in the Kristiania valley, where numerous brick-fields with 

 an abundance of excellent sections have facihtated investigations. 



The experience gathered from these investigations shows 

 that we can distinguish between a deep-sea clay in the lower 

 parts of the valley, up to about 100 — 130 m. above the sea 

 {the younger area elay), and another clay deposited in some 

 more shallow water in the higher parts of the valley, from about 

 100 — 175 m. above the sea [the younger portlandia clay). 



The fauna of the younger area clay of the Kristiania 

 valley comprises, so far as is hitherto known, 37 species of 

 mollusca [lepeta coeca and eulima stenostoma, Jeffr. are to be 

 added to the list on pp. 156, 157). This fauna comprises a 

 number of boreal forms in addition to the arctic; the proportion 

 of arctic and boreal forms is about ^/s : ^/s. 



The fauna of the younger area clay is thus no more a 

 high arctic, but a horeo-arctic one a conclusion that is also 

 corroborated by the size of the high arctic species such as area 

 glacialis and siphonodentalium vitreum. The climate during 

 the deposition of the younger area clay near Kristiania has 

 thus probably been about the same as it is at present in Fin- 

 mark. A list of foraminifera of the younger area clay will be 

 found on pp. 161, 162. 



In the younger portlandia clay, the fauna comprises only 

 a few species {portlandia lenticida, leda permda, pecten grøn- 

 landicus and axinus fiexuosus are the most common species). 



Pp. 178—182. E. Clay Deposits from the Last Part of the 



Subsidence. 



After the retreat from the third series of terminal moraines, 

 in the Kristiania valley, etc, a new pause of the ice-border has 

 deposited a series of moraines behind the clay terrace of Lilie- 

 strømmen. Further, during the continual receding of the ice, a 

 fifth long pause has tåken place south of the ends of the large 

 lakes of central Norway (Mjøsen, Hurdalsvand, Randsfjord, Spir- 

 ilen, Krøderen, etc). At this fifth station of recession, the most 



