394 RAMBLES OF A GEOLOGIST. 



der, tucked up her little blue cloak over her head, and hied 

 away to the chapel. 



In the Free Church pulpit I recognised an old friend, to 

 whom I introduced myself at the close of the service, and 

 by whom I was introduced, in turn, to several intelligent 

 members of his session, to whose kindness I owed, on the fol- 

 lowing day, introductions to some of the less accessible curio- 

 sities of the place. I rose betimes on the morning of Mon- 

 day, that I might have leisure enough before me to see them 

 all, and broke my first ground in Orkney as a geologist in a 

 quarry a few hundred yards to the south and east of the 

 town. It is strange enough how frequently the explorer 

 in the Old Red finds himself restricted in a locality to well 

 nigh a single organism, an effect, probably, of some grega- 

 rious instinct in the ancient fishes of this formation, similar 

 to that which characterizes so many of the fishes of the pre- 

 sent time, or of some peculiarity in their constitution, which 

 made each choose for itself a peculiar habitat. In this quarry, 

 though abounding in broken remains, I found scarce a sin- 

 gle fragment which did not belong to an exceedingly mi- 

 nute species of Coccosteus, of which my first specimen had 

 been sent me a few years before by Mr Robert Dick, from 

 the neighbourhood of Thurso, and which I at that time, 

 judging from its general proportions, had set down as the 

 young of the Coccosteus cuspidatus. Its apparent gregarious- 

 ness, too, quite as marked at Thurso as in this quarry, had 

 assisted, on the strength of an obvious enough analogy, in 

 leading to the conclusion. There are several species of the 

 existing fish, well known on our coasts, that, though solitary 

 when fully grown, are gregarious when young. The coal- 

 fish, which as the sillock of a few inches in length congre- 

 gates by thousands, but as the colum-saw of from two and a 

 half to three feet is a solitary fish, forms a familiar instance ; 

 and I had inferred that the Coccosteus, found solitary, in 



