20 P. A. øyen [No. 12 



most probable that this part, F, of the section is representing 

 the deposition from the beginning of the Sveneng period to the 

 end of the Romerike-stage and that the division G is the result 

 of deposition during the Mytilus-si&ge and during the Portlandia- 

 stage and, of course, more especially during the latter one. There 

 is no reasonable inducement to assume any marked deposition to 

 have tåken place in this locality during the Littorina- stage. 

 And, already during an early part of the Pholas-stage erosion 

 of the littoral belt commenced in this region to be later on 

 followed with fluviatile erosion and decomposition of the material 

 of the up-heaved terraces. Of course the correlation with the 

 upper part of the section of Kilebu is quite clear. The corre- 

 lation now made only from petrographical constitution and stra- 

 tigraphical appearance is to be in a deeper sense testified to in 

 comparing the biological facts. 



The lower part of the Rakkestad section, viz. a portion 

 corresponding with the layers B — E proved to be relatively rich 

 in fossils. The following species were found: — 



Yoldia hyperborea Lov. of quite the same type as that 

 above mentioned from Braarudaas near Horten (Christiania 

 Vid.-Selsk. Skr. I. Math.-Naturvid. Kl. 1908, nr. 2, p. 34). 



Portlandia lenticula Møll. was very common either in a 

 more slender variety or a more rugged one being more beaked 

 and having more prominent marks of growth. No less than 

 seventy two specimens were collected, but only as casts in quite 

 the same manner as the other fossils of this deposit. The 

 maximum length of this species was measured to be 6,5 mm. 

 As a rule it occurred as complete specimens. 



Leda pernula Mull. forma typica. Length 15 mm. My 

 little son, Tor, collected two very fine and complete east specimens 

 of this species. 



Axinus flexuosus Mont. A very fine east of the arctic 

 variety was found measuring 6 mm. of length. 



Siphonodentalium vitreum M. Sårs. A rather fine east 

 of the common type. 



