490 



H. HICKS ON THE REMAINS OF PLANTS FROM THE 



is certain ; and marine plants probably lived in abundance. The cel- 

 lular structure of the marine plants, however, rendered them so 

 readily liable to decomposition, that it is not much to be wondered 

 at that their remains are seldom found. The various markings 

 which have been attributed to land and marine plants in the earlier 

 rocks may in some cases have been produced by them ; but others, 

 as shown by Salter, must have been tracks produced by worms. 

 Of the most important of those about which doubt still remains may 

 be mentioned Eophyton of Torell, from the Lower Cambrian rocks 

 of Scandinavia, but which I have also found at St. David's. Oruziana, 

 from the Lingula-flags of North Wales, supposed by Salter to be a 

 worm-track, I believe, from evidence I have been collecting for some 

 time, will prove to be an Alga. Buihotrephis, found in the Lingula- 

 flags and in the Arenig rocks in Wales, and by Prof. Nicholson in 

 the Skiddaw Slates of Cumberland*, but first discovered and de- 

 scribed by Prof. Hall in America, appears also to be allied to the 

 Algae. Of Eophyton ? eocplanatmn, which I found in the Tremadoc 

 rocks of St. David's, I fear the evidence is scarcely sufficient to ally 

 it with land plants. Its strong tubular structure renders it unlike 

 any known land plant; and the only other fossil found yet to which 

 it can be compared is the Pyritonema of Prof. M'Coy, placed by him 

 amongst the Zoophytes, though its true nature is still a matter of 

 much doubt. 



Appendix. By E. Etheridge, Esq., F.K.S.. Pres. Geol. Soc. 



Early in the present month Dr. Hicks brought for my inspection 

 several slabs of micaceous sandstone, having upon their surfaces 

 numerous fragments of carbonaceous matter, which possessed no 

 definite shape or apparent structure. Their general appearance, in 

 some cases, was that of decomposed coniferous wood, in others, 

 resembling bundles of finely striated black or dark-brown carbon, 

 brittle or tough, the black portions being by far the most brittle ; 

 the lighter and darker remains, however, undoubtedly belong to the 

 same plant, but differently mineralized. Hitherto, in Britain, no 

 true plant-remains are known to occur below the Upper Ludlow, 

 and the only recognized species in that formation is Pachytheca, or 

 Pachy sporangium. Between the Upper Ludlow and the base of the 

 Denbighshire Grits no traces whatever of plant-remains have yet 

 occurred in British Silurian strata. 



Dr. Dawson, as far back as 1859, in his paper upon the " Possil 

 Plants from the Devonian Bocks of Canada"f, described, amongst 



* The fossils formerly placed by Prof. Nicholson in the genus Buthotrephis, 

 from the Skiddaw Slates, have been since redescribed by him and Dr. Dawson 

 under the generic name of Protanmdaria. 



t Quart. Journ. Geol. Soc. vol. xv. p. 484. 



