32 LITTORINID^:. 



a short internal process (analogous to the byssiferous stylet of 

 Mytilus?), which lies in a slanting direction with the outer 

 point towards the tail : opercular lobe of the same colour as the 

 sole : appendage whitish and conspicuous. Shell thinner, with 

 a longer spire, often smaller, and usually ribless. E. data, 

 Phil. I. c. t. xxiii. f. 3. 



Habitat : Zostera and seaweeds, from low tide-mark 

 to a few fathoms, on nearly every part of our coasts ; 

 although it is rather local. The 1st variety occurs at 

 Tenby and in Dublin Bay, the 2nd was found at Poole 

 by Mr. Barlee, and the 3rd frequents estuaries and 

 brackish water. The typical form is fossil at Belfast 

 (Grainger) ; Bute (Smith) ; Uddevalla (Malm) ; post- 

 glacial beds in Norway, 50-150 feet (Sars) ; and Sicily 

 (Philippi, as R. ventricosa) . Its foreign range in a living 

 state extends from Norway, where it is very large (Loven 

 and others) , to Malaga (M f Andrew), Dalmatia (Brusina), 

 Corfu (Hanley, as R. elata), Black Sea (Middendorff, 

 as R. oblong a and R. elata), Algeria (M 'Andrew and 

 Weinkauff), and Canary Isles (v.Mohrenstern), at depths 

 varying from low-water to 35 f. Philippics specimens 

 of his R. venusta were Venetian. 



The animal occasionally floats, or suspends itself by a 

 viscous thread. The shell varies greatly in size, thick- 

 ness, and length of spire ; but it may always be known 

 from R. violacea and R. costulata by its wide mouth, 

 plain and scarcely perceptible transverse striae, and the 

 tooth or fold on the pillar. 



The synonyms are inconveniently numerous. Some 

 of them are (either certainly or probably) Turbo costatus, 

 Pulteney, T. labiosus, Montagu, R. oblonga, R. ventri- 

 cosa, and R. hyalina, Desmarets, R. grossa and R.fragilis, 

 Midland, R. turricula and R. pulla, Brown, and R. Sou- 

 ley etiana, Recluz. R. cornea of Loven may be also a 

 local variety. 



