I903- 53 



NOTES. 



ZOOLOGY. 



Tidal Fringes. 



While walking on the sea-shore, and especially on a strand, one may 

 sometimes see, usually at high-water mark, a fringe of marine debris, 

 largely composed of sea-weed with a few species of shells. This is 

 generally the result of stormy weather, and experienced workers know 

 that such debris yields, now and then, prizes when least expected. 

 There is another class of tidal fringe, however, found along our strands, 

 to which I desire to call attention ; a fringe formed usually of one species, 

 which comes in at the edge of a quiet sea, generally in summer or early 

 autumn. The first of these I remember noticing was a very narrow line 

 of the snow-white Miliolina secans, a porcellanous member of the Fora- 

 minifera, that stretched all the way from Portrush to the White Rocks. 

 This is common on some shores mixed with other species ; here it was 

 by itself Mr. J. Wright, to whom I brought some of this fringe, tells 

 me that Messrs. Stewart and Swanston found Trtmcatnlina lobatula under 

 similar circumstances on a strand of the Dingle promontory. On this 

 same strand at Portrush, also on a quiet September day, I found the 

 exquisite spiral shell of Spirula Peronii dotting the tide mark here and 

 there for over a mile. The maiority were much broken, but I obtained 

 eight or ten nice specimens. I have noticed shells of this little tropical ^ 

 Cephalapod on several other occasions at both Portrush and Port- 

 stewart, but never saw the animal. At the latter strand I have noted 

 the Cowrie, Trivia europaa, coming in plentifully along the margin of a 

 quiet tide, but in nothing like the quantity which Mr. Frank Bigger 

 and myself once found as a thick tide-fringe on Ocean Strand near 

 Portsalon. We brought away several thousands of the finest specimens. 

 This is the best locality I know in Ireland for this pretty shell ; for 

 Messrs. Darbishire and Standen found it there in even larger quantities 

 Hydrobia ulvce occasionally occurs as a fringe at the mouth of the Boyne, 

 and in Belfast Lough. The violet pelagic shell, lanlhina rotundata, is 

 carefully watched for on the north coast each summer and autumn. It 

 sometimes sparingly fringes high-water-mark along Bush Bay and 

 Ballycastle strand, and I have watched it coming in alive with its float 

 on Finner Strand, Bundoran, during a westerly gale. On Boxing-day, 1901, 

 along the Inner Bay of Dundrum, there was a thick fringe, in some 

 places over an inch deep, of young specimens of the common crab 

 Carcinas mcBiias. The tide recedes far at this southern end, and it is 

 possible a sharp frost while tide was out may have caused the death of 

 these myriads, which the incoming tide quietly floated up later to high- 

 water mark. The Banded Wedge-shell, Donax vitiatus, a common bivalve 



' Native habitats— West Indies, S.K. Asia, Australia 



