179 

 "LITTORINA LITTOREA (L.) : A DOUBTFUL RECORD." 



By J. C. DACIE. 



(Read before the Society, September 8th, 1915). 



The note by Rev. Dr. A. H. Cooke in this Journal, vol. 14, p. 305, 

 much interested me, as I somewhat speciaHze in the British Littorince, 

 and have collected them in Scotland, in Islay, lona, Oban and neigh- 

 bourhood, Kyle of Loch Alsh, Stornoway (Hebrides), Thurso and the 

 Pentland Firth, Stromness and neighbourhood (Orkneys), at Lerwick, 

 Scalloway, Hillswick and neighbourhood (Shetlands), and on the east 

 coast from Duncansby Head to Musselburgh. 



Now, unless Mr. C. G. Hewitt walked into the lairs of some oyster 

 catchers, or other sea fowl, the Littorina, which he records as having 

 found " living in the crevices of the rocks at the top of Ruadval in 

 St. Kilda, at a height of almost 450 feet above sea-level," was 

 decidedly not L. littorea L., but would doubtless be that variety of 

 Littorina rudis (Mat.), which — for want of a better name — is termed 

 var. jugosa Mont. 



From my experience with this Littorma — after several visits to the 

 Orkney and Shetland Islands — I would say that it can be found on 

 any of the rocky headlands and upon the cliffs of Scotland which are 

 exposed to the full force of the Atlantic breakers. But, unless one is 

 disposed to risk one's neck in seeking for it, it will escape collection 

 altogether. In fact, it was not till my fourth visit to Stromness, in 

 1905, that quite by chance I reached Bigging Brough, a Plutonic 

 headland which lent itself to an easy descent from the cliff to the 

 actual sea shore, and that in this descent I was introduced to this 

 special form of Littorina rudis (Mat.). 



Since that date I have collected this Littorina twice in the Shet- 

 lands, and have discovered that it can always be found by descending 

 from the top of the cliffs to exposed ledges of rock, where (in July 

 and August, the months of my visits) the molluscs can only obtain 

 water from the rains, which occur there very frequently, and that it 

 can only be during the autumn and winter storms that the spray of 

 the Atlantic ever reaches them. 



At that wonder of wonders in rock scenery — the " Grind of the 

 Naver " — and the Villians of Ure, near to the Head of Stanshi in 

 Shetland, I found this Littorina at a tremendous height above sea- 

 level and quite a quarter of a mile from the sea. 



I have not yet visited the north-west and west coasts of Ireland, 

 but would hazard that upon those rocky headlands and cliffs this 

 Littorina would be found. 



