Correspondence. 429 



with nearly all the groups already found, scarcely a vestige being 

 seen in most of the beds which separate the several colonies, upon 

 which usually we come quite abruptly. This I look upon also as one 

 of the chief causes why a Lower Cambrian fauna has not ere now 

 come to light. 



I am, sir, yours truly, 

 St. David's, Henry Hicks. 



1th August, 1867. 



PHOLAS-BOEINGS IN DEVONSHIRE. 

 To the Editor of the GEOLoaiOAL Magazine. 



Sir, — As I have observed in your journal for July some remarks 

 on Pholas-borings found 200 feet or more above the present high- 

 water-mark, on the cliffs in the neighbourhood of Torqiiay, perhaps 

 one or two words on these ancient rock-perforations may not be out 

 of place by one who has more than once made them the object of his 

 search and examination. 



Some time ago, in the year 1864, I happened to be visiting Ilfra- 

 combe and its neighbourhood, and, amongst other coast scenery, I 

 spent a day on Woollacombe sands, extending my ramble to the 

 summit of the hills called Morte Point, not forgetting to search care- 

 fully far above the present sea level, its rocky wall and face, when 

 practicable, for the marks or signs of some ancient stone-boring 

 moUusk. 



And here I ought to mention that Mr. Pengelly was the first 

 person from whom I learnt the supposed origin of these peculiar 

 marks or holes in rocks near the sea-coast. As I minutely looked 

 over its pointed heights facing the sea, after some trouble I found a 

 number of perforations from an inch to two inches in size, and about 

 one inch or a little more in depth. I cannot speak exactly, as I 

 write now from my recollection of what I then saw. 



Some of the rock-cuttings were much worn by the action of the 

 weather : some, no doubt, were naturally formed by frost and other 

 causes ; while some, in a more sheltered part of the hill, appeared 

 nearly as perfect as when left by their excavators. 



In my own mind the evidence is so conclusive that these small 

 hollows are Pholas-borings, or the work of some Mollusk, and that 

 the rock, now 200 feet or more above the sea-level, must have been 

 once under water at every tide. 



Some five or six years before this examination of the hills at 

 Morte Point, I happened to be staying in Plymouth, and, having a 

 little spare time on hand, I closely explored the rocks which fringe 

 the sea-beach below the Hoe, and there I found a number of freshly- 

 formed holes in the limestone rock, covered at every tide, about the 

 size of the Pholas-borings, only they extended much deejDer in the 

 rock, while at the same time there appeared to be a kind of hard, 

 shining coating on the inside of their holes, much like the irmer 

 part of an almond shell. The reason, perhaps, why these ancient 

 stone-borings are seldom noticed, is the fact, I think, that the old 

 sea-coast is partly washed away, for it is only (so far as my observa- 



