0, 



n a former occasion the author described some shell- 

 banks (Det sydlige Norges „boreale" strandlinje. Christiania Vid.- 

 Selsk. Forh. 1906, Nr. 1) that were regarded as constituting a 

 rather well characterized stratigraphical horizon, the Mactra- 

 niveau (L. c. p. 10). And, on a later occasion (Christiania Vid.- 

 Selsk. Skr. Mathm.-Naturvid. Kl. 1908, N. % p. 118) the border- 

 ing levels of this stratigraphical niveau were dessignated as 

 ninety and sixty-five metres above sea-level, the Mactra-niveau 

 itself, or rather the littoral deposits of it, being confined within 

 these boundaries. 



In the summer-months of 1904 I had an opportunity to 

 investigate a highly interesting deposit that proved to be amply 

 fossil-bearing, and the very favorable situation of this locality, 

 within the very boundaries of the town of Christiania itself, 

 made it possible for me to follow the excavations in a rather 

 great detail. The excavation mentioned were caused by some 

 intended foundation works on number 6 and 8 in the Street 

 of Brochmann in the northern part of Christiania on the right or 

 west side of the River of Akerselv at a height of 89,110 metres 

 above sea-level or rather above the datum-line of the administra- 

 tion of harbours in Christiania. The results of the investigations 

 above mentioned, however, remained unpublished as I enter- 

 tained a faint hope of being able to extend the investigation 

 in order to get a more complete material for an accurate de- 

 scription of this interesting deposit. But, in spite of my visiting 

 this locality several times a year ever since I did not succeed in 

 adding anything, neither as to stratigraphy nor in the respect of 

 fossil material, to the observations and collections made during 



