PROCEEDINGS OF GEOLOGICAL SOCIETIES. 
297 
J, I although Dr. Wright had proposed the following classification — 5. Ammo- 
I nites Bucklandi zone ; 6. A. Planorbis zone (including the White Lias and 
, the Ostrea beds) ; and 7. Avicula contorta zone, yet he preferred to group 
y them thus — 5. A. Bucklandi zone; 6. A. Flanorbis zone; 7. Enaliosaurian 
p| zone ; 8. White Lias ; 9, Avicula contorta zone : 8 and 9 being equivalent to 
jj I the " Kossener Schichten" or " Rhsetic beds" of Giimbel and other Conti- 
^ nental geologists. 
u I The arguments in favour of his views the author based chiefly on ob- 
^ servations made at Beer-Crowcombe, Stoke St. Mary, Pibsbury, Long Sutton, 
J and other places in Somersetshire ; and on a critical examination of the sections 
p at Street, Saltford, &c. as given by Dr. Wright. 
The communication concluded with descriptions of upwards of sixty species 
of fossils belonging to the Rhsetic beds of England (including their thin re- 
presentatives discovered by the author in the Vallis near Frome) ; twenty-eight 
of these species are ne\v. 
Juneb,mA. 
1. "On the Occurrence of some large Granite Boulders, at a great depth, in 
West Rosewanie Miue. Gwiuear, Cornwall." By H. C. Salmon, Esq., F.G.S. 
' The boulders of granite referred to were found in the 50-fathom level below 
the adit, the adit being 2 J; fathoms from the surface. One of the boulders 
; was 4 feet 2 inches, and another 3 feet 10 inches in diameter; there were five 
other smaller boulders or pebbles also met with in the level. The boulders are 
in the killas close to the lode, and both the lode and the "country" near the 
lode are made up of brecciated killas. After quoting the details of somewhat 
similar phenomena formerly observed at Relistian and Herland Mines, the 
author treated of the probable origin of the boulders in question ; and al- 
though lodes are regarded by some as having been formed from below upwards, 
yet in this case the author thinks that the boulders must have had a common 
origin with the lode, and have been introduced by a fissure from the surface. 
2. " On an erect SigiUaria from the South Joggins, Nova Scotia." By Dr. 
J. W. Dawson, E.G.S. 
This specimen, presenting the external markings of leaf-scars and ribs with 
more than usual clearness and with some instructive peculiarities, has afforded 
I to the author the type of a new species, SigiUaria Brownii. Observations on 
the probable style of growth, on the structure, and on the classification of 
SigiUaria, were also given in this paper, together with a resume of the obser- 
vations previously published regarctng SigiUaria by Brongniart, Corda, and 
others. 
3. "On a Carpolite from the Coal-formation of Cape Breton." By Dr. 
J. W. Dawson, E.G.S. 
Numerous Trigonocarpa belonging to a new species {Trigonocarpum Hookeri) 
occur in a thin calcareous layer in the coal-measures near Port Hood, Cape 
Breton. The author thinks it highly probable that, though some Trigonocarpa 
may have belonged to Conifers, yet in this case they were the seeds of Sigil- 
laria. 
4. " On a Reconstructed Bed on the top of the Chalk." By W. Whitaker, 
Esq.-, B.A., F.G.S. 
At some places near Reading (Maidenhatch Farm, about six miles to the W. ; 
and Tilehurst, two miles to the S.W,), and also near Maidenhead, from 18 to 
twenty feet of broken chalk overlies the true chalk ; and in places is overlain 
by the bottom-bed of the Reading Beds, and therefore must have been recon- 
structed before the deposition of the Tertiary strata. For the most part, how- 
ever, in Berkshire the Woolwich and Reading beds rest on an undisturbed sur- 
face of the Chalk. Li Wiltshire, also, the author has observed similarly con- 
structed chalk, probably there also underlying Tertiary beds \ and he suggests 
VOL. IV. 2 H 
