﻿SUMMARY OF THE CONTENTS. 713 



Pp. 601 — 610. A number of boreal species have also pro- 

 bably immigrated into the Kristiania fjord in recent times {tel- 

 lina pusilla, macoma tenuis, psammobia tellinella, rupicola 

 distorta, neæra rostrata, etc). Among these species, mya 

 arenaria is of speciel interest. The hypothesis is maintained, 

 that this species also has perhaps immigrated from the west. 



Pp. 610 — 613. Among the lusitanic species probably immi- 

 grated to the fjord in recent times may be noted lima Mans, 

 modiolaria marmorata, nucula nitida, trochus zizypMnus, 

 and perhaps also several small species (see p. 612). 



As a main result of the comparison of the recent mollusc 

 fauna of the Kristiania Fjord with the youngest postglacial fauna, 

 it is maintained that the boreal element is more predominent in 

 the recent fauna. The table (p. 614) shows the successive 

 changes of the mollusc fauna from postglacial to recent times: 



Fauna of the upper tapes-banks, etc. . . 



— - - Iower — . . 



Recent fauna of the fjord (above 30 fath.) 



The study of these changes proves further, that the cli- 

 mate during the tapes-time must have been milder than the 

 present climate; the amount of the difference is estimated at 

 2° C. 



A comparison with known results drawn from the flora, 

 etc, is summansed on pp. 615 — 622. 



A discussion of the question of the time elapsed since the 

 beginning of the tapes-time (i. e. the time of the Littorina sea 

 in the Baltic area, the time of the kitchen-middens of Denmark 

 and Jæderen, etc.) is given on pp. 622 — 625. The hypothesis 

 of Ekholm, estimating this time to about 9000 years, is there 

 considered probable. 



Pp. 625 — 650 contain a discussion of the question whether 

 oscillations of level and climate have occurred in the Kristi- 

 ania region since the epiglacial time. 



