Salter and Hicks—Menevian Fossils. 51
and Littleham Bay "Waterstone beds" and pseudomorphous crystals of chloride of sodium occur. I agree with Mr. Symonds that the beds found near Exmouth are Waterstone, but I have not been able to find there any trace of the pseudomorphous crystals.
In communications made by Mr. Strickland (Quart. Journ. Geol. Soc. Vol. ix. p. 5) and myself (Quart. Journ. Geol. Soc. vol. iv. p. 273, & vol. ix. p. 185) it has been shown that these pseudomorphs are found in Nottinghamshire, Cheshire, Worcestershire, and Gloucestershire. I have found them in Somersetshire (at Blackbrock, near Taunton), and now on the south coast of Devon; they therefore occur over the greater part of the area of the Trias in England.
On a small fragment of Waterstone that I picked up on the beach at Exmouth, the marks very closely resemble the reptilian traces found in the Keuper of Runcorn, in Cheshire. As the fragment is small, and reptilian traces have not been found in the Trias in Devonshire, I cannot speak with certainty, but mention the matter in order that the attention of other observers may be drawn to it. A series of small "throws down" to the west appear to intersect the Trias between Culverhole point and Exmouth.
3. On some Fossils from the "Menevian Group." By J. W. Salter, Esq., F.G.S., A.L.S., and Henry Hicks, Esq.
(Read June 17, 1868*.)
[Plates II. & IIL.]
Descriptions of some of the principal fossils of the Menevian formation, including the large Paradoxides (P. Davidis), appeared in the Quarterly Journal of the Society for August 1864, and others in the number for November 1865; but as many new forms have been obtained since then, a large number yet remain to be described. The continued research, carried on by one of the authors, in the typical locality, St. David's, has been the means of discovering the whole of these new forms, many of which, however, have been subsequently found in various other places. Around the Merionethshire anticlinal ridge of Lower Cambrian rocks large collections have been made:—on the north side, near Maentwrog, and at Tafarn Helig, near Trawsfynydd, by Messrs. D. Homfray and R. A. Eskrigge; and on the south side near Dolgelly by Messrs. T. Belt, E. Williamson, J. Plant, and J. C. Barlow,—all of whom have also done something towards defining the boundaries of the group in North Wales. Much also has been done by us, in like manner, in South Wales, and many new localities have been found to be occupied by this interesting group.
The range of some of these fossils has been more clearly ascertained, and greatly extended. They are not in any way limited to the black Lower Lingula-shales, but occur also in the hard grey rocks which form the upper bands of the Harlech grits.
One of the authors has recently found both Trilobites and Shells
- For the other Communications read at this Evening Meeting, see Quart.
Journ. Geol. Soc. vol. xxiv. p. 484.
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