Trof. NordemMold — Expeditmi to Greenland. SSS- 



entirely to disappear in tlie upper part, tlie occupation of tlie 

 districts to the north by the ice-sheet after it had deserted the Chalk, 

 and the connexion of that event with the non-occurrence of Nucula 

 Cobboldia in Scotch and other Glacial beds, which. I assign to a stage 

 in the retreat of the ice- sheet posterior to the desertion of the Chalk, 

 will, I think, be better understood. Nevertheless, according to my 

 view, neither the 100 feet below nor the 100 feet above represent 

 the whole glacial sequence, there being glacial beds anterior to the- 

 one and posterior to the other. 



I would take this opportunity of adding that the Brick Clays witb 

 Mollusca of Scotland, which I thought might, from their resting on 

 the Till, be of Post-glacial age, seem to me on further consideration 

 to belong to the Glacial period, though to the later part of it ; and I 

 would ask Mr. Geikie if not merely the Scotch Till, but the clay h.& 

 distinguishes from it and calls Boulder-clay, and the intercalated and 

 subjacent silt, clay, and gravel, be the equivalents, as he contends, of 

 the East Anglian and Holderness deposits, how it happens that not. 

 one of the several shells unknown as living, or as living nearer than 

 the Pacific, which these East Anglian and Holderness Beds yield, has 

 occurred in the many Scotch deposits which yield Mollusca thus 

 grouped by him as equivalents of the East Anglian and Holderness 

 beds — a part of the question which he has avoided encountering 

 altogether. 



V. — Account of an Expedition to Greenland in the year 1870i. 



By Prof. A. E. Nordenskiold. 



Foreign Correspondent Geol. Soc. Lond., etc., etc., etc. 



Part II. 



(PLATE VIII.) 



{^Continued from page 306.) 



THESE holes in the ice filled with water are in no way connected" 

 with each other, and at the bottom of them we found every- 

 where, not only near the border, but in the most distant parts of the 

 inland ice visited by us, a layer, some few millimetres thick, of grey 

 powder, often conglomerated into small round balls of loose con- 

 sistency. Under the microscope, the principal substance of this 

 remarkable powder appeared to consist of white angular transparent 

 grains. We could also observe remains of vegetable fragments ;, 

 yellow, imperfectly translucent particles, with, as it appeared, evident 

 surfaces of cleavage (felspar ?) ; green crystals (augite) and black 

 opaque grains, which were attracted by the magnet. The qiiantity 

 of these foreign components is, however, so inconsiderable, that the 

 whole mass may be looked upon as one homogeneous substancCi. 

 An analysis by Mr. G. Lindstrom of this fine glacial sand gave — 



Silicic acid 62-25 



Alumina 14-93 



Sesquioxyd of Iron 0-7,4 



Protoxyd of Iron 4-64 



Protoxyd of Manganese 0-07 



Lime 5-09 



