390 The American Geologist. December, 1894 
ing wholly different from the drift-wood cast on the shores of 
Spitzbergen, which is borne by the Gulf Stream into the 
North Atlantic and Arctic oceans. 
"We may add, in this connection, that Gen. A. W. Greely's 
Report of the U. S. Expedition to Lady Franklin bay, Grin- 
nell land, mentions (in vol. it, p. 57) the occurrence there of 
recent fossil shells of Astarte lactea up to 1,000 feet, and of 
Saxicava arctica, as provisionally determined, up to 2,000 feet 
above the sea. At Polaris bay on the neighboring Greenland 
coast, recent marine shells are reported to occur at the hight 
of 1,600 feet, 
It may be also noted that one of the questions which we 
may hope to have answered, if Nansen crosses the polar sea 
and reaches home, relates to the geographic position and ex- 
tent of the large nearly flat land from which come the great 
tabular icebergs, sometimes called floebergs and "palreocrystic 
icebergs," similar to the vast masses shed from the Antarctic 
ice-sheet, though smaller, ranging from 100 to 600 feet and 
rarely 800 or 900 feet in thickness, seen by Nares and others 
in the open polar sea north of Greenland and Grinnell land. 
These flat icebergs, born from the margin of an ice-sheet on 
flat and comparatively low land, unlike that of the Greenland 
ice-sheet and its valley glaciers, are thought by Greely to 
come from a large land area north of Bering strait and very 
near the pole, with its center between the 86th and 88th par- 
allels and the 155th and 175th meridians of west longitude. 
The thick tabular bergs are prevented from drifting to the 
Siberian coast by the shallowness of the sea there ; but they 
are carried by the currents to Banks land, Grinnell land, and 
into Robeson and Kennedy channels, where the Atlantic tides 
sweeping around the north end of Greenland turn south to 
Smith sound. 
Numerous glaciers by which the Greenland ice-sheet out- 
flows through the valleys of its mountain border into Melville 
bay and Inglefield gulf, between 75° and 78° north latitude, 
are described by Prof. Angelo Heilprin.* Among the illus- 
trations accompanying his paper, the most interesting are the 
"hanging glacier" of Herschel's island, flowing down from the 
*Populaf Science Monthly, vol. xi.vi, pp. 1-14. with nine illustrations 
from photographs, Nov., 1894. 
