Triassic Flora of Richmond. — Marcou. 163 
coal field in 1848. Taylor thought, with some doubt, that they 
belonged to the Coal Measures, in his first paper of 1834, and 
in his Statistics of coal of 1848 he seems to adopt Lyell and 
Bunbury's reference to the Jurassic series ; and the brothers 
Rogers and Lyell regarded them as the equivalent of the 
Lower Oolite coal of Whitby in Yorkshire, and Brora in 
Scotland. 
Second period, 1849-1882. — In April, 1849, I made a careful 
exploration of a part of the Richmond coal field, round the 
mines of Gowrie, Mid-lothian and Blackheath pits, collecting 
a great number of fossil plants, and a few fossil fishes. When 
there my impression was that the series of strata belonged to 
the Trias. The upper portion of the series, more especially on 
account of the great quantity Equisetuin related to Eq. 
Goluranare and of a Calamites related to Cal. arenacexts, re- 
minded me in the most striking way of the coal field of the 
Keuper of Franche-Comte, and of the Basel canton (Swit- 
zerland), and of the Schilfsandsteine (Reed-cane sandstone) 
of the vicinity of Stuttgart and Tiibingen. 
After my researches in the field, I visited at Philadelphia, 
in company with professor Louis Agassiz — who was then 
delivering a course of lectures there — Mr. Richard C. Taylor, 
who asked my opinion upon the age of the Richmond coal 
field, I said that it was Triassic, and the upper part of the 
series of strata, just at the oj^ening of the Mid4othian coal 
pit, was certainly Keuperian. Taylor seemed to agree with 
me, saying that he had abandoned the idea that it was the 
Coal Measures ; but that it seemed to him older than the 
Whitby formation of Yorkshire, well known to him. Agassiz 
was very sure that the fossil fishes belonged to forms indi- 
cating the Liassic age, but not more recent at all events. 
I wrote then a paper entitled : Note sur la homille du 
comte de Chesterfield pvi^s de Richinond^yfhich was published 
in the "Bulletin Soc. Geol. France," vol. vi, Juin, 1849, con- 
taining the following conclusions : "I am inclined to think 
that the coal formation of the vicinity of Richmond is older 
than the Lower OiJlite, and belongs either to the Keuper or 
the Lias, with a greater probability in favor of the Lias, on 
account of the fossil fishes." 
As a practical geologist, my opinion was that the coal for- 
mation of Richmond was the equivalent of the European Trias. 
