380 Proceedings of the Royal Physical Society. 



No remains of any organism have yet been obtained from 

 the Lewisian rocks in Scotland, but it would be unsafe to 

 infer from this fact that life did not exist within the area 

 during their accumulation. Certain cherts, limestones, and 

 dark graphitic schists, mapped by the officers of the Geo- 

 logical Survey in the Loch Maree district of Eoss-shire, 

 probably owe some of their characters to organised 

 matter. 



In the Torridonian formation, radiating bodies like gigantic 

 sponge-spicules were met with by the Geological Survey, in 

 shales near Stoer in Sutherlandshire, that were once believed 

 to be of organic origin; but there is more reason to consider 

 that they are purely mineral. 



Worm tracks and casts have been met with in several 

 places, especially in the shales of the lowest members of the 

 formation. In 1898 the collectors of the Geological Survey 

 vigorously searched the beds most likely to yield fossils, 

 but with little success, worm tracks only having been 

 found. Certain dark phosphatic nodules were observed, 

 however, in the highest beds of the formation, which occur 

 on the Cailleach Head, near the mouth of Little Loch Broom. 

 Some of these nodules have been microscopically and chemi- 

 cally examined by Mr Teall. Their chemical composition 

 itself was sufficient to make it highly probable that they 

 had an organic origin; and this obtains confirmation from 

 the fact that certain spherical cells and brown coloured 

 fibres, which appear to be the debris of organisms, were 

 observed in them by Mr Teall. These are the first actual 

 organic remains that have, as yet, been recorded from the 

 Torridonian formation in Scotland.^ 



In the year 1891, during the progress of the Geological 

 Survey of West Eoss-shire, Messrs J. Home and A. Mac- 

 conochie found the head-shields of a trilobite in the Fucoid 

 beds, and Serpulite Grit at Allt Eigh Ian and Lochan Md, in 

 the Dundonnell Forest, south of Ullapool.^ The trilobite 

 remains proved to belong to a species of Olenellus very near 

 to 0. TJiomsoni, the original form found in the Georgian or 



^ Mem. Geol. Sur., "Summary of Progress for 1899," p. 185, 1900. 

 '^ Ann, Rep. Geol. Sur., 1891, p. 384, 1892. 



