6 P. A. OYEN [No. 12 



little previously, nowhere subsequently to the formation of that 

 extended moraine range (I. c, p. 76). 



In the month of June in 1899 I carried my first excursion 

 with University students to the clay-pits of the brick-works in 

 the surroundings of Moss. On that occasion a visit was also 

 paid to the tile-work of Moss near Verlebugten. Subsequently I 

 have almost annuly inspected the clay-excavations in this place 

 either alone or accompained by University students, down to the 

 time when the tile-work became abolished. In the summer of 

 1911 I even had the pleasure to be accompanied in this place 

 by my friend F. W. Harmer, the eminent British Crag-explorer, 

 who took a great interest in the phenomena here represented. 

 And, indeed, the picturesque landscape around the inner part of 

 the Verlebugt as this may be viewed from the outer or peri- 

 pheric slope of the ra-moraine (as represented in Pl. II, Fig. 1) is 

 highly attractive not only to foreigners but also to Norwegians 

 themselves. To the geologist, howewer, the ra-moraine itself (as 

 represented in Pl. II, Fig. 2) is forming the most important 

 subject, and, to the palæontologist the fossil-bearing clay just 

 at the tile-work that we see in the right portion of the picture 

 is of a peculiar interest as it is crowded with valves of the 

 following arctic molluscan species, viz. Portlandia arctica, 

 Gray, Macoma calcaria Chemn., and Saxicava arctica L., 

 and from the first one of these species also derived the name 

 Yoldia-clay, often used to designate the deposit in question. 



The base-layers of the fossil-bearing clay in this section we 

 are obliged to trace below sea-level, and we may follow the 

 fossiliferous clay mixed with stones and intercalated with alter- 

 nating sand-layers up to about ten metres above sea-level. The 

 upper part of it could be seen in steep walls, between six and 

 seven metres high in the clay-pits of the tile-work. And, above 

 the fossil-bearing clay a covering of water-vvorn gravel of a 

 thickness of half a metre was seen. The superficial layer, 

 Ihowever, in some places to the thickness of between one and two 

 imetres consisted of a rather fine sand of yellowish-brown colour. 

 This sand, no doubt, is to be regarded as a washed residual 



