10 LITTORINIDjE. 



off Lundy Island (M f Andrew) ; Manorbeer, Pembroke- 

 shire (J. G. J.) ; Isle of Man, " one broken specimen 

 from deep water on the north coast " (Forbes) ; Nymph 

 bank, 50 f. (M f Andrew) ; Bantry (Miss Hutchins, 

 Thompson, and Barlee); Dublin Bay (Turton and Brown); 

 Belfast Bay (Hyndman) ; off Lame, co. Antrim, 18-20 f. 

 (J. G. J.) ; Lough Strangford, 7-20 f. (Dickie) ; Tyn- 

 ingham sands, N.B. (Brown); Lamlash (Landsborough); 

 Loch Fyne, and the Hebrides as far north as Stornoway 

 (Barlee and J. G. J.). A single dead and worn speci- 

 men of the variety was found by me at Herm ; it may 

 belong to a distinct species or be exotic. R. cancellata 

 is fossil in the Sussex beds (Godwin-Austen) ; Ireland 

 (J. Smith) ; Calabria (Philippi) . Its living range is 

 mostly southern, from Cherbourg (Becluz and Mace) 

 and Morbihan (Tasle) to the Gulf of Gascony (D'Or- 

 bigny pere, and J. G. J.), and Corunna (M' Andrew and 

 H. Woodward) , throughout the Mediterranean (Michaud 

 and others) ; Adriatic (Heller) ; Dalmatia (Brasilia) ; 

 Mogador, 3 f. (M'Andrew); iEgean (Forbes, fide M 'An- 

 drew) ; Madeira, 15-24 f., and Canary Isles, 12-60 f. 

 (M f Andrew). The last-named naturalist also took some 

 dead specimens in his Norwegian dr edgings. 



It is active and bold, floats like its congeners, and 

 spins a byssal thread instantaneously on being detached 

 from a crawling position. The incessant play of the cilia 

 that fringe the tentacles is very striking ; it appears to 

 be caused bv the action of a double row of muscles in 

 each tentacle, arranged in the form of a siphon, which is 

 perceptible through the transparency of the integument. 

 The pallial filaments probably serve the purpose of sup- 

 plementary tentacles to warn the animal of impending- 

 danger. In spite of its stoutness the shell is sometimes 

 perforated, possibly by Murex erinaceus or M. corallinus. 



