1913] THE QUATERNARY SECTION OF FOSS 15 



In the series just in question, however, it occurs in a smaller 

 variety partly of another shape, and only in the clay-layers. 

 Here we may note two different varieties, the one of an oblong 

 shape measuring 8 mm. in length and 5 mm. in height, and the 

 other one belonging to a rather short and high type measuring 

 7 mm. in length and 6 mm. in height, thus carrying the cha- 

 racters of var. septentrionalis. The former one of these two 

 variteties especially occurs immediately above the sand-layer c, 

 the latter one, however, especially occurs between the sand-layers 

 a and c. Portlandia lenticula Mull. was rather rare in the 

 preceding series, but here in this series it is very numerous, 

 especially in the lower part, a, b and c, occurring there as well 

 in the clay-layer as more especially in the two sand-layers a 

 and c during the deposition of which it proves to have been 

 swarming as in these layers numerous specimens, especially 

 smaller ones, were found, often of the oval type in which it may 

 easily be confounded with juvenile specimens of Portlandia 

 arctica Gray. Nucula tenuis Mont. is nearly of the same type 

 as in the preceding series. Abra longicallis Sc. occurs in the 

 typical form but is accompanied by A. nitida Mull. as in the 

 preceding series. From this one was above mentioned also the 

 occurrence of Axinus flexuosus Mont. In the series in question 

 beside this species was also found another one that most pro- 

 bably ought to be referred to Axinus gouldii Phil. occurring, 

 however, in rather small specimens. At last we ought to note 

 the want of Siphonodentalium vitreum Sårs. 



XIX. This deposit is a complex one too. And, in ascending 

 order the following separate layers may be distinguished: — 



a. Clay, thickness 10,5 cm. 



b. Sand, thickness 6 mm. 



c. Clay, thickness 25 cm. or rather alternating layers of 

 clay and sand. 



d. Sand, thickness 15 mm. or rather alternating layers of 

 sand and clay. 



In this series the clay is of yellowish-grey colour, and it is 

 rather fine-grained and mixed with a little fine-grained sand in 



