50 PROCEEDIXGS OF THE GEOLOGICAL SOCIETY. [Jau. 5, 



a peculiar value, and should be kept, in the hope that further Ught 

 may be thrown upon them. The absence of articulations may be a 

 character of these fossUs, and not due to obliteration, though such 

 obhteration is common in specimens of Calamite from the Carboni- 

 ferous sandstone, and it is said that Calamites of considerable length 

 have been found, presenting no appearance extemaUy of articulations, 

 whilst the cast always presents them. It should also be remarked, 

 that there are obscure traces in two specimens of transverse raised 

 knobs and bars (perhaps spirally arranged), crossing the strise. 

 obhquelv : these may indicate a pecuhar character of the plants, but 

 more probably have been caused by pressure during silicification. 



Note on the Age and Relative Position of the Sandstone con- 

 taining Fossil Plants at Lerwick in the Shetland Isles. 

 By Sir Roderick I. Mtjrchison, E.R.S., G.S. 



In presenting to the Society, on the part of my friend the Right 

 Hon. Henry Tufuell, the specimens of fossil plants which he brought 

 last summer from Lerwick, in the Shetland Isles, and on the botanical 

 affinities of which, Dr. Hooker has reported at my request, I 

 suggested that the rock in which these remains occurred must be 

 considered as the upper member of the Old Red Sandstone. 



Having traced sandstones of similar lithological character from the 

 south side of the jMurray Firth near Elgin through Ross and 

 Caithness to the Orkney Islands, and ha-^-ing seen that in their range 

 they everywhere constitute the upper member of the Old Red Sand- 

 stone, I could not entertain a doubt that the " superimposed second- 

 ary Shetland sandstone" of Dr. Hibbert * was of similar age. A mere 

 inspection of the Map of that author showed that the crystallme 

 rocks of Shetland were overlaid by conglomerates, schists, flagstones, 

 and sandstones, as in the Orkney Islands and the adjacent mainland 

 of Caithness. I am confirmed in this opinion, by learning from 

 Mr. Tufnell, that fossil fishes had also been found in the Isle of 

 Bressey, adjacent to the port of Lerodck. 



Since then, I have consulted the only two living geologists with 

 whom I am acquainted who have actually visited Shetland, Dr. Traill, 

 and the Rev. Dr. A. Flemiug, and I find that they both entertain 

 the same opinion as myself concerning the age of the sandstones in 

 question. The latter, though not so fortunate as to procure specimens 

 of any animal remains, thus speaks of the few vegetable remams he met 

 with : — " Some of these, usually very indistmct and often converted 

 mto anthracite, resembled the leaves of flags, whilst other specimens 

 bore a remote analogy to that I supposed might have been a com- 

 pressed Stembei-gia. Tlie general character of the rocks led me to 

 regard them as nearly of the age of the gi'ey sandstone, and a part of 

 the series occurring in Caithness and Orkney, &c." 



Dr. Traill, who is so well versed in the structure of the Orkney 

 Islands, and is known to palaeontologists as the discoverer of many of 



* Description of the Shetland Islands, with a Geological Map, Plates, &c. 

 4to. Edinburgh, 1822. 



