REI.TCS OF THE PERMO-CARBONIFEROUS ICE AGE. 
1 7 
crucialis, Hudleston ; Rhombopera tenuis, Hinde ; Athyris 
Macleayana, Eth. Fil. var. ; Productus semireticulatus, 
Martin ; Aulosteges, sp. nov. ; and Dielasma, sp. nov. 
At a point in the Wyndham River just north of the 
Range, through which it has cut a channel, is another 
section showing the boulder bed (Fig. 5, Plate IV). The 
deposit, which does not attain any greater thickness than 
three feet, is crowded with boulders and pebbles of granite 
and crystalline rocks embedded in a calcareous fossiliferous 
matrix (Fig. 6, Plate V), which contains fragments of 
Spirifera, Productus and Polyzoa, in addition to Aviculo- 
pecten tenuicollis. The bed in which these pebbles and 
boulders occur is, beyond all doubt, of marine origin, as is 
proved by its fossil contents ; it therefore can hardly be 
a glacial moraine, and it is more than likely that the 
materials of which the bed was made up were trans- 
ported by floating icebergs, that drifted seawards after 
they had been broken off from some extensive glacier 
which came down to sea level. 
It is well known that whenever glaciers descend to 
sea level, and extend into the sea, huge icebergs break off 
and float away. These icebergs are often loaded with 
debris of all kinds of rocks, and very great physical results 
must ensue from the scattering of such large quantities of 
material over the sea bottom. Antarctic icebergs also 
carry a similar burden, and glacial conglomerates are actually 
forming at the present time. 
One of the Arctic navigators, Col. Fielden, in an ac- 
count of his visit to the Kara Sea, off Nova Zemblya, in 
the years 1895 to 1897, gives a graphic description of how 
at the present day icebergs may be seen loaded with debris 
of every conceivable kind. This author emphasises the effects 
which must ensue from the annual transport of burdens of 
mud, shingle and sand, which are carried by the ice-floes and 
distributee! over the floor of the ocean. In north latitude 
69° 40', and east longitude 57 0 12', Col. Fielden encountered 
numerous icebergs covered with gravel and silt. In Dolga 
Bay, while scrambling over the dripping, rolling and melting 
pack-ice, this observer was very forcibly impressed with 
the enormous quantities of detritus, stones, gravel and 
mud on the surface of the floes, and which on melting w r as 
thrown to the bottom of the sea. It is impossible to esti- 
mate the amount of material thus transported into the 
Kara Sea, but from Col. Fielden's account it appears not 
only to have been enormous, but during the course of ages 
must have exercised great influence in decreasing the depth 
of that sea and forming beds not unlike the Lyons Glacial 
Conglomerate. Marine boreal beds appear to be very 
