1913] THE QUATERNARY SECTION OF FOSS 19 



layers thin as paper or of a ihickness of about one millimetre 

 alternating; as a mean thickness ,we may assume about half a 

 millimetre. The sand is of a grey colour with a faint dash of 

 red. No reaction to HG is to be observed. In some portions 

 the sand has a nearly black colour in other ones the colour is 

 somewhat brown. The thickness of this sand-layer series is about 

 25 or 30 centimetres. This series is fossil-bearing as not only 

 leaves, Uwigs and trunks of trees oceur but also remains of fresh- 

 water mollusca. The remains of trees proved lo belong to 

 Alnus sp. as determined by my friend professor Gran. The 

 remains of fresh-water mollusca proved to belong to Anodonta 

 cygnea Lin. var. anatina Lin. the remains of the epidermis 

 being rather thick and the shape of the species being very nearly 

 that figured by Forbes ånd Hanley (History of British Mollusca 

 Vol. II, pp. 155—161) or Jeffreys (British Gonchology, Vol. I, 

 pp. 44—45, and Vol. V; Pl. 3, Fig. 2). This variety is still living 

 in our country as desbribed by Miss Esmark (Land- and Fresh- 

 water Mollusca of Norway, 1886, pp. 124-^-125). The fossil- 

 bearing layers sometimes is in part a little crumbled or folded 

 so as to indicate some pressure having acted upon them. De- 

 composition has also in part tåken place as a boulder of clay- 

 schist was found the outer part of which had become changed 

 into a coat of marl to the thickness of about one centimetre 

 giving a strong reaction to HC1. This fresh-water deposit may 

 have been formed in a small pond or it may possibly have been, 

 deposited in a small lagoon near the mouth of the river at a 

 time when sea-level just took this position. The fossil-bearing 

 sand-layers of this deposit were covered with decomposed or 

 weathered material of a clayey or sandy character with numerous 

 stones and blocks of an edged shape, or indeed, these stones 

 and blocks were quite predominating. This upper deposit had 

 a thickness of about 25 centimetres but it had been levelled 

 with the foundation plane so it may indeed have been of a greater 

 thickness. The grey or yellowish clay of this covering layer in 

 some places gave a faint reaction to HC1. 



