Mineralogy of Sky, 31 



ing shells is here included between two beds of quartz rock ; un- 

 fortunately but a small quantity of the rock is exposed, and as' it 

 lies low on the shore it is impossible to trace the series to the 

 extent which is desirable. As far as I could conjecture the quartz 

 rock was a portion of the general series which alternates with the 

 mica slate : if this be correct it offers a solitary example of a rock 

 containing organized remains alternating with the series of mica 

 slate, a fact as yet so anomalous that it must not be received with- 

 out much more decided evidence than that which I have here 

 produced. I have to regret that the loss of these specimens pre- 

 vents me from describing the particular shells which I observed in 

 this limestone ; yet doubtful as this fact appears even to myself, it 

 is somewhat countenanced by a circumstance not dissimilar which 

 occurs near Borrereg on the side of Loch Eishort, where the white 

 and crystalline quartz rock which alternates with the mica slate is 

 found in one place alternating for a short space with the blue lime- 

 stone and red sandstone, the two first and lowest members of the 

 secondary strata. With every wish to find that I had committed 

 an error in this examination I could not detect it, and must there- 

 fore suffer the whole to remain at present as I have stated it, an 

 example at least of a most deceptive geological appearance if it 

 shall not turn out to be an interesting fact. 



The two associated rocks which I have here described are imme- 

 'diately followed by a regular succession of stratified rocks which 

 I shall now proceed to detail ; commencing at Loch Eishort, as 

 being the principal point in which I observed their contact with 

 the former, and from which I derived the clue to the order of suc- 

 cession of all the stratified rocks in Sky. 



In distinguishing however the rocks which follow by the term 

 stratified, I am far from meaning to say that I consider the mica 



