216 R. L. JACK AND R. ETHER1DGE, JTJX., OX PLANTS
the Sequence of the Strata in the Old-Red-Sandstone series of South Perthshire" (Quart. Journ. Geol. Soc. xviii. p. 253, read 16 April, 1862). This paper will be afterwards referred to.
In the fourth edition of ' Siluria,' published in 1867, Sir R. I. Murchison gave figures of the chief vegetable remains of the Scotch Old Red*. The longitudinally fluted stems mentioned by previous writers as common throughout the formation were microscopically examined by Prof. Quekett, and found to exhibit true coniferous structure, approaching that of the Araucarian group.
Mr. W. P. M'Nab communicatedf his researches into the structure of Hugh Miller's Cromarty lignite, which had been previously ex- amined by Prof. Xicoll. Mr. M'Xab pronounces the structure ex- hibited by these sections to be allied to the Coniferae, but not refer- able either to Dadoxylon or Dictyoceylon, as surmised by Mr. Salter: he proposes the name of Pcdcvopitys Milleri for the Cromarty lignite, and pronounces it distinct from the coniferous wood examined by Prof. Quekett for Sir P. I. Murchison.
The welcome appearance, in 1871, of Dr. J.W. Dawson's monograph of the Devonian and Silurian plants of Canada j, published by the Geological Survey of Canada, not only afforded botanists an oppor- tunity of becoming acquainted with the British-Xorth-American fossil flora of those periods in a collective form, but, what was of equal importance, put us in possession of Dr. Dawson's notes on Mr. C. W. Peach's extensive collection of Scotch Old-Red plants. En the latter, Dr. Dawson noticed two species of Psilopliyton, one allied to- P. prineeps, Dn., the other to P. robustius, Dn. There are three species of Lepidodendron : one, perhaps L. notlium, Salter, Dr. Dawson considers closely allied to his L. gaspianum ; the second is allied to Cyclostigma densifolium, Dn. ; and the third, that described by Salter as Lycopodites Milleri, he considers an herbaceous plant. The collection also contains a Cyclopteris (allied to C. Broivnii, Dn.), a Calamites (near C. transitionis, Dn.), Stigmaria, bark of iSigillaria, a plant probably allied to Anarthrocanna , and pieces of Coniferae §.
In 1872, Mr. C. W. Peach delivered a Presidential Address to the Royal Physical Society of Edinburgh, " On the Fossil Flora of the Old Red Sandstone of the Xorth of Scotland," when drawings of all the discovered forms were exhibited. In the ' Journal of Botany ' for 1873 Mr. Carruthers gave a paper " On some Lycopodiaceous plants from the Old Red Sandstone of the North of Scotland." He there refers the fragments figured by Miller, on plate vii. of the ' Old Red Sandstone,' to Dawson's Psilophyton, and proves that the coniferous rootlets of Salter are really the upper branches of his Lepidodendron nothum and Lycopodites Milleri, all of which Carruthers considers identical with Psilopliyton (IJaliserites) Dechenianus, Gbppert ; further, Caulopteris Peachii, Salter, is probably a fragment of a large plant allied to Psilopliyton robustius, Dn.
- Op. cit. p. 269, foss. 73. t Trans. Bot. Soc. Edinb. 1870, x. p. 312.
% The Fossil plants of the Devonian and Upper Silurian Formations of
Canada, pp. 92, pis. xx. 8vo. Montreal, 1871. § Op. rif. p. 77.
