Geological Society. 153 
PROCEEDINGS OF LEARNED SOCIETIES. 
GEOLOGICAL SOCIETY. 
May 25, 1881.—Robert Etheridge, Esq., F.R.S., 
President, in the Chair. 
The following communications were read :— 
1. “On the Discovery of some Remains of Plants at the Base of 
the Denbighshire Grits, near Corwen, North Wales.” By Henry 
Hicks, M.D., F.G.8. With an Appendix by R. Etheridge, Esq., 
F.R.S., Pres. Geol. Soe. 
Traces of these fossils were first observed in 1875, by the author, 
in Pen-y-glog quarry, about two miles east of Corwen. Further 
research has resulted in the discovery of more satisfactory specimens, 
which have been examined by Messrs. Carruthers, Etheridge, and 
EK. T. Newton. Among them are spherical bodies resembling the 
Pachytheca of Sir J. D. Hooker, from the bone-bed of the Ludlow 
series, supposed to be Lycopodiaceous spore-cases ; also numerous 
minute bodies, stated by Mr. Carruthers to be united in threes and to 
agree with the forms of the microspores of Lycopodiacex, both recent 
and fossil; and some fragments which may belong to these plants, 
and others probably belonging to plants described by Dr. Dawson 
from the Devonian of Canada under the name of Pstlophyton. The 
above testify to the existence of a very rich land-flora at the time. 
Mixed up with these, however, are numerous carbonaceous frag- 
ments of a plant described also by Dr. Dawson from the Devonian 
of Canada, which he referred to the Conifer, but which is, accord- 
ing to Mr. Carruthers, an anomalous form of Alga, The former 
called it Prototaxites; the latter renamed it Nematophycus. Nume- 
rous microscopical sections, showing the beautiful structure of this 
interesting plant from the specimens found at Pen-y-glog, have been 
examined by Mr. Etheridge and Mr. Newton; and their conclusions 
agree with those of Mr. Carruthers. The evidence seems to show 
that at this mid-Silurian period the immediate area where the plants 
are now discovered must have been under water, and that the mix- 
ture of marine and dry-land plants took place in consequence of 
floods on rapid marine denudation. The author indicated that the 
land-areas must have been to the south and west, chiefly islands 
surrounded by a moderately deep sea in which Graptolites oceurred 
in abundance. The position of these beds may be stated to be about 
2000 feet below the true Wenlock series, and about the horizon of 
the Upper Llandovery rocks. 
2. “ Notes on a Mammalian Jaw from the Purbeck Beds at Swan- 
age, Dorset.” By Edgar Willett, Esq. Communicated by the Pre- 
sident. 
Excavations were undertaken last summer in this locality (Durl- 
stone Bay, Swanage), where, rather more than twenty years since, 
Ann. & Mag. N. Hist. Ser. 5. Vol. viii. 11 
