436 H. Keeping—Bembridge Fossils on Creechbarrow Hill. 
structure may be seen to curve round and cross the centre of the 
glacier, forming great loops directed down-stream. The veining and 
ribboned structure are nearly parallel with the sides and bottom of 
the glacier, and where the surface is being rapidly melted the lower 
horizontal veins near the middle come to the surface and form these 
loops. Forbes appears to be quite correct when he says ‘‘ the vertical 
structure is too close to the original strata of the névé to allow of the 
supposition that these have all of a sudden turned up vertically in 
some parts of the glacier, and disappeared in the remainder”. 
In the cave which was made in the lower portion (which has now 
melted away) of the Upper Grindelwald glacier I have seen the ice 
built up of more or less regular layers of flat ice granules, the whole 
appearing like a mass of masonry or ribbons of grains. The shear- 
planes cutting the granules and giving rise to this ribboning are 
produced by slow shear without fracture parallel to the direction of 
flow. This regular structure produced by shear is not commonly seen 
in ice caves, for they are generally excavated at the ends of glaciers 
where the rate of distortion 1s small. Where this masonry-like 
structure crops out on the glacier it discloses itself as ribboned 
structure. As before remarked it is generally parallel with the 
veined structure, and seems to make it more striking. On the Rhone 
glacier the ribboned structure is shown up by the dirt which settles 
in the parallel fissures produced by the melting of the ice along the 
shear-planes. Where streams cut into the ice it is frequently well 
shown. 
Both the veined and ribboned structure will be found most perfectly 
developed when the glacier is moving rapidly and the internal strains, 
i.e. rate of distortion, is greatest. When a glacier widens, becomes 
thin, or for any reason moves slowly, the slow alterations which are 
constantly taking place in the shape of the grains gradually obliterates 
the structure. Owing to the motion the structure is also carried to 
portions lower down the glacier than those where it is being 
produced, and in crevassed areas the veins and ribboned structure 
are twisted about in a very striking manner. The time required for 
the grains to appreciably alter their form and size must be measured 
in years. 
IJ].—On THE piscoveRY oF BrmpripceE Limesrone Fossmzs on . 
CreecHBArrow Hitz, Iste or PurBecx. 
By Henry Kenrine, Sedgwick Museum, Cambridge. 
(PLATE XXXIV.) 
HEN last year I had an opportunity of examining a few rocks 
and fossils from the limestone of Creechbarrow Hill, which the 
late Mr. W. H. Hudleston considered of Bagshot age, I at once 
suspected that they belonged to the Bembridge Limestone. Upon 
my pointing this out to Professor Hughes he requested me to go down 
to examine the ground, which I did in November of last year, but 
I found only the same fossils which Mr. Hudleston had recorded, namely, 
Melanopsis and Paludina. On my return to Cambridge I expressed the 
opinion that better evidence would probably be obtained if a few 
openings were made here and there, and the Professor arranged that 
| 
