418 PROFESSOR GEIKIE ON THE 
may be searched with considerable hope of success. I could not find, indeed, 
any trace of fish remains among them. Dr HEppLz, however, informs me that 
he was shown some ichthyolites (Coccosteus, &c.) in Bressay, which he was 
assured had been found among the flagstones of that island. But in some of 
the flaggy beds near Lerwick the little Estheria, so common near Thurso and in 
different parts of Orkney, has been met with.* In the sandstone quarry at the 
south end of Lerwick many plants occur in the form of casts.t They consist 
of stems and roots. The stems, sometimes in fragments five or six feet long, 
are fluted longitudinally, like Calamites, to which genus they were referred by 
Dr Hooker. As he pointed out, however, they have no articulations, but, on 
the contrary, show traces of projecting knobs, perhaps spirally arranged. I 
found the stems to be sometimes dichotomous, and to be furnished with massive 
divergent roots, like the knarled terminations of old dwarf Scotch firs. They 
suggested Sigillaria rather than Calamites as their probable analogue. They 
are known as the “ Corduroy” plants of Shetland. 
In the dark shaly beds at Sand Lodge many small forms of vegetation occur. 
They have evidently been much macerated previous to deposition. I procured 
some which looked like the ill-preserved raches of ferns, but too indefinite for 
identification. Further search, however, at that locality is desirable. 
4, Volcanic Rocks.—On the west side of the Mainland of Shetland Dr 
FLEMING observed that red sandstone occurs on either side of Papa Sound, | 
at the south end of St Magnus Bay, and he suggested that it belonged to the 
so-called “independent coal-formation” of the Wernerian school.{ He showed 
that it was associated with certain amygdaloids and claystones. Since the 
appearance of his paper about seventy years ago, no one, so far as I know, 
has published any further account of these rocks. In Dr FLEemine’s descrip- 
tion, which is written in the true Wernerian style, no reference is of course 
made to volcanic action, or to the intrusive character of any of the rocks. Yet 
he was so accurate and minute in his observations, that knowing the volcanie 
history of the Old Red Sandstone on the south side of the Grampians, I had 
long believed from his narrative that a somewhat similar history must await 
deciphering in the far north among the western islands and voes of Shetland. 
It was with considerable interest and pleasure that I visited that region m 
company with Mr B. N. Peacu, and found a fine series of natural sections, in | 
which the existence of volcanic activity at the northern extremity of the British 
area during the Old Red Sandstone was admirably demonstrated. 
The sandstone which occurs on the Mainland at Melby, between Norbie 
* Murcuisoy, “Quart. Journ. Geol, Soc,” xv. p. 413, 
+ See Hooxsr, Jbid. ix. p. 49. 
t “Mem. Wernerian Soc,” vol. i. 

