566 H. W. FEILDEN AND C. E. DE KANCE ON 



are obliterated ; but numerous fragments of these terraces preserved 

 by a protective snow mantle remain to attest their former continuity. 



Sea-ice driven on shore by gales, or moving up and down with 

 the tides, is a very potent factor in glaciating rocks and pebbles. 

 Along the shores of the Polar Basin this process of glaciation was 

 seen in progress by one of us ; and he records in his ' Journal ' that at 

 the south end of a small island in Blackcliff Bay (lat. 82° 30' N.) 

 the bottoms of the hummocks, some eight to fifteen feet thick, were 

 studded with hard limestone pebbles, which were rounded and 

 scratched as distinctly as others taken from moraines; when ex- 

 tracted from the ice, only the exposed surfaces, as a rule, were 

 glaciated. As the tide recedes the hummocks do not always arrive 

 at a position of rest without some disturbance of the subjacent 

 material, particularly on a shelving shore, and the sliding of the 

 hummock to a lower level and the sound following on the grating 

 together of the pebbles beneath may be noted. In many places 

 where gaps occurred in the lines of ancient sea-terraces, the base- 

 ment rock, as well as some of the pebbles in the terraces, were 

 found to be glaciated, and there can be no doubt that this is due to 

 the action of shore-ice, the condition of the terraces precluding the 

 idea that it might have been the result of glacier action. 



Pushed-up mounds or long ridges of gravels, both at the sea-level 

 and at various elevations, are a conspicuous feature along the shores 

 of the Polar Basin ; these sometimes extend at the edges of deltas in 

 long lines of mounds like giant mole-hills. 



A careful examination of the fossil remains found in the recent 

 beds of Grinnell Land and North Greenland, extending from an 

 altitude of 1000 feet to the present sea-level, give unmistakable evi- 

 dence that the fauna is practically identical with that now existing 

 in Grinnell Land as well as in the neighbouring sea. The remains 

 of Mammalia, such as the lemming {My odes torquatus), the ringed 

 seal (Phoca hispida), the reindeer (Oervus tarandus), and musk-ox 

 (Ovibos moschatus), were discovered in these beds. The marine 

 Mollusca most abundant as living species in the adjacent seas, such 

 as Pecten groenlandicus, Astarte borealis, My a truncata, and Saxicava 

 rugosa, are also the most abundant species throughout the mud-beds, 

 whilst the stems of two species of Laminaria, which appear to grow 

 in considerable abundance in the Polar Sea, were detected in mud- 

 beds, at an elevation of 200 feet, still retaining their peculiar sea- 

 shore odour. Coniferous drift-wood, of precisely the same character 

 as that now stranded, was found at elevations of several hundred 

 feet, and so little altered by time or climate that it still retained its 

 buoyancy. The species of the Post-tertiary and Recent Mollusca 

 have all been determined by Dr. Gwyn Jeffreys, who has described 

 the collections made by the Expedition at twelve stations*, and 

 identified those from Stations 13 to 27, described by one of usf. 



* " The Post-tertiary Fossils procured in the late Arctic Expedition ; with 

 Notes on some of the Eecent or Living Mollusca from the same Expedition," 

 Ann. & Mag. Nat. Hist. 1877, vol. xx. p. 229-242. 



t "Post-tertiary Beds of Grinnell Land and North Greenland," by H. W. 

 Feilden, E.G.S., C.M.Z.S., with Note by J. Gwyn Jeffreys, LL.D., P.R.S., Ann. 

 & Mag. Nat. Hist. 1877, vol. xx. pp. 483-494. 



