iV PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Feb.1ge2, 
sometimes diallage, sometimes rather acicular hornblende, sometimes 
glaucophane, but generally smaragdite; the felspathic constituent 
passing from a rather changed felspar to the so-called saussurite ; 
garnets are sometimes common, and white mica occasional; these 
different kinds pass one into another. The rock also varies greatly 
in coarseness, and often exhibits a distinctly streaky structure. He 
described the locality where the rock occurs in situ. 
Dr. Vaueuan Cornisn, in exhibiting photographs of ‘ Snow- 
Mushrooms’ taken by him in January 1901, at Glacier House, 
near the summit of the Canadian Pacific Railway in the Selkirk 
Mountains, west of the Rockies (British Columbia), altitude 4000 
feet, said that the snowfall had been 25 feet measured, then 
represented by a 5-foot layer upon the ground. It is said that 
there is not much wind here, and that the snow mostly falls 
at a temperature near the melting-point. It has the reniform 
habit in great perfection, and its clinging masses are very beautiful. 
The most remarkable thing about it is the formation of symmetrical 
caps, which overhang by a yard and more the supporting pedestal. 
The stumps of the felled trees usually have bases 2 to 4 feet in 
diameter, which support the whole depth of snow and are frequently 
of such a height as to produce, with the cap of snow, an almost 
perfect reproduction of amushroom. Their nearly perfect symmetry 
was attained, he believed, by gradual growth until the lhmit of 
cohesion was reached in all directions. The tree-stumps being almost 
exactly circular, the complete cap is also circular. These caps are 
very stable, the great weight of superincumbent snow welding the 
lower layers into a tenacious mass. Their study has, at least, a 
suggestive value for geologists. 
Prof. Lapworts referred to the good work that Dr. Vaughan 
Cornish was doing in observational science by his photographs of 
the various surface-shapes assumed by water, sand, snow, etc., 
under the undulatory movements of the wind. He spoke of. the 
resemblances of many of these shapes to well-known geological 
fold-forms, and gave it as his opinion that the symmetrical mush- 
room-like snow-shapes shown upon these beautiful photographs 
were the effects of symmetrical wind-eddies, and might be compared 
with the so-called ‘mushroom-folds’ and mountains without roots 
of the pre-Alpine regions, shapes also probably due to more or less 
symmetrical tri-dimensional movements. 
The following communications were read :— 
1. ‘On a new Genus belonging to the Leperditiade, from the 
Cambrian Shales of Malvern.’ By Prof. Theodore Groom, M.A., 
Dse., 1.6.8. 
2. ‘The Sequence of the Cambrian and Associated Beds of the 
Malvern Hills.” By Prof. Theodore Groom, M.A., D.Sc., F.G.S. 
With an Appendix on the Brachiopoda by Charles Alfred Matley, 
Esq., B.Se., F.G.S. 
