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Darwin Correspondence Project

From A. C. Ramsay   [27–30 June 1859]1

It is a good thing to have friends to point out ones errors.2

I believe it is certain about the worm holes in the Longmynd. I do not doubt it having often seen them. The trilobite I do consider to be doubtful in spite of Salters confidence in the matter.3 The specimen is in our gallery.4 The rocks I have no doubt are lower than Barrandes primordial Zone. I think that certain.

I lately heard from Sterry Hunt of Canada5 that fossils had been found in the Crystalline limestone of the Laurentian Gneiss. They are said by Billings6 to be Corals. The Laurentian Gneiss is you probably know, said to be the oldest rock in N. America. It was certainly metamorphosed in the extremest way, before the deposition of the Lingula flags which lie quite unconformably upon it. I say so from personal knowledge. It is said by Logan7 that on Lakes Huron & Superior the Huronian rocks,——Longmynd, lie between the Laurentian Gneiss & the equivalents of our Lingula flags. I have heard however, but not from Logan, that possibly the Huronian rocks are Lingula flags also. In the mean while I accept Logans view, for he knows most about them.

If you take the Saturday Review you would see a notice of the Laurentian rocks a few weeks since. It was in the 1st of 2 articles on Rogers Pennsylvania.8

Ever yours siny | Andw C Ramsay

CD annotations

scored pencil
3.0 Laurentian] underl pencil
Top of first page: ‘22’9 brown crayon


The letter was written between the letters to A. C. Ramsay, [26 June 1859] and 1 July [1859].
CD had called Ramsay’s attention to differences between Ramsay’s and Louis Agassiz’s account of the Jura gravels. See letter to A. C. Ramsay, 24 June [1859] and n. 5.
John William Salter, who worked with Ramsay on the Geological Survey, described worm holes and a possible new genus of trilobite in the Longmynd deposits in 1856. He named the trilobite Palæopyge ramsayi (see Salter 1856).
The Museum of Practical Geology, owned by the Geological Survey, was in Jermyn Street, London. Ramsay was currently classifying the rock specimens for a catalogue (Geikie 1895, p. 259).
Thomas Sterry Hunt was on the staff of the Geological Survey of Canada.
Elkanah Billings was a naturalist with the Geological Survey of Canada.
William Edmond Logan, the director of the Geological Survey of Canada, was the first to describe the Huronian and Laurentian rocks.
The anonymous review of Rogers 1858 appeared in two parts in the Saturday Review, 30 April 1859, pp. 530–1, and 28 May 1859, pp. 658–60. The review may have been by Ramsay, for in 1859 he began contributing geological articles to this periodical (Geikie 1895, p. 260).
The number of one of CD’s portfolios of notes on palaeontology and extinction.


Geikie, Archibald. 1895. Memoir of Sir Andrew Crombie Ramsay. London and New York: Macmillan.

Rogers, Henry Darwin. 1858. The geology of Pennsylvania. A government survey with a general view of the geology of the United States, essays on the coal-formation and its fossils, and a description of the coal-fields of North America and Great Britain. 2 vols. in 3. Edinburgh and London: W. Blackwood and Sons. Philadelphia, Pa.: J. B. Lippincott.


No doubt about worm-holes in the Long Mynd, and they are certainly lower than J. Barrande’s primordial zone. Fossils in Laurentian gneiss.

Letter details

Letter no.
Andrew Crombie Ramsay
Charles Robert Darwin
Sent from
Source of text
DAR 205.9: 400
Physical description
ALS 3pp inc †

Please cite as

Darwin Correspondence Project, “Letter no. 2845,” accessed on 22 September 2023,

Also published in The Correspondence of Charles Darwin, vol. 7