Correspondence — Rev. W. S. Symonds. 239 



would gain access to the district having at the time of the last submergence been to 

 some extent choked with ice, which thus checked the tidal action inland from the 

 present coast ; and thought that possibly both glaciers and the sea had to- 

 gether contributed towards the formation of the terraces. These, he observed, 

 were by no means confined to Gley Eoy itself, but were to be seen on a large 

 scale, and at a lower level in the valley of the Spean, if not elsewhere. 



Mr. Prestwich observed that both sides of the question had an d priori argument 

 in their favour. There was no doubt of the almost universal glaciation or of the 

 depression below the sea to a depth of at least 1000 feet, and therefore that marine 

 action was possible. The circumstance of the cols marking the height of each terrace 

 was, however, strongly in favour of the freshwater theory ; but, on the other hand, 

 there seemed an absence of suflSciently elevated land in the Glen Eoy district for the 

 origination of a glacier, such as was required by this theory. 



The Chairman suggested the necessity of actual sections being made to show the 

 nature of the terraces and the condition of the rocks below. He referred to a case on 

 a much larger scale in the Tungma valley of East Nepaul, recorded by Dr. Hooker, 

 in which the phenomena at Glen Roy were repeated on a larger scale, and, in con- 

 nexion with each terrace, a glacier and its moraine could be traced. 



coie-iaEs:poi>rx):Bisrc:E]. 



FISH-REMAINS IN THE DEVONIAN BEDS OF CORNWALL. 



Sir, — In 1868 1 recognized, in Mr. Pengelly's collection of Cornish 

 fossils at Torquay, the structure of the Upper Silurian and Old Eed 

 fish Pteraspis or Scapliaspis, in the supposed coral the Steganodictyum 

 Cornuhicum of McCoy. This identification was afterwards confirmed 

 by Prof. Huxley and Mr. Ray Lankester, and it has an important 

 signification upon the question of the age of the rocks of South 

 Devon and Cornwall, inasmuch as the Pteraspis has, I understand, 

 been found by Mr. Etheridge in the lower Devonian rocks of Lynton 

 and Lynmouth. 



As I am not aware that any further investigations have been 

 carried on as regards the Cornish rocks, the following notes may 

 have some interest for those amateurs in geology who, like myself, 

 enjoy passing leisure hours in the investigation of the records of 

 the rocks. 



When on a visit to Penzance in February last, I took the oppor- 

 tunity of examining, through the courtesy of the Hon. Curator, the 

 collection of Looe and Polperro fossils presented by Mr. Peach, 

 Mr. Couch, and others, to the Museum of the Eoyal Geological Society 

 of Cornwall. It appears that as early as 1846, these fossils were 

 described by Mr. Peach as the remains of fish, in the Transactions 

 of the Geological Society of Cornwall, from specimens found by Mr. 

 Couch at Scilly Cove, on the east side of the harbour at Polperro. 

 From what I saw in the Penzance Museum, I determined to examine 

 the Looe and Polperro district, and requested my friend SirW. Guise, 

 who had already gone over with me the Old Eed districts of Here- 

 fordshire and Monmouthshire, and the rocks of North Devon, to 

 join me at Plymouth. Our time was limited, and I can only say 

 that I wish we had gone earlier, for I know of no district more 

 likely to repay the geologist for prolonged and thorough investiga- 

 tion. The place for head-quarters should be that romantic little 

 town Polperro, which may be best reached from Liskeard, and where 



