46 LITTORINID^. 



and Plymouth (J. G. J.). The variety occurred to me 

 in the laminarian zone at Skye, and the "Whalsey Skerries 

 in the east of Shetland. Fossil in the post-glacial beds 

 of Norway from the present level of the sea to 100 feet 

 above it (Sars). This author has also noticed it living 

 on the Norwegian coasts as far north as Oxfjord in 

 Finmark ; I found it at Etretat in Normandy, Martin 

 in the Gulf of Lyons, Mace at Antibes, and Philippi at 

 Sorrento and Palermo. Although local, it is not un- 

 common. 



It is an active and restless little creature. I observed 

 in this and other species ofRissoa an upward and down- 

 ward current or movement on the surface of each ten- 

 tacle, apparently caused by the action of the cilia. 



Having carefully compared British and Mediterranean 

 specimens, I still believe that Philippics description and 

 figure of R. soluta fairly represent our shell. It varies 

 considerably in the length and compactness of the spire, 

 as well as in the degree of sculpture. Indeed the 

 striae cannot be detected in most specimens unless by 

 means of a high magnifying-power, which possibly 

 Philippi was not in the habit of using. He especially 

 mentioned the umbilical fissure that characterizes the 

 present shell. Searles Wood proposed to call our species 

 intersecta, in case its identification with Philippics species 

 should prove to be erroneous; Bean gave it the MS. 

 name of minutissima, and Martin that of globosa. The 

 last two names I have seen in collections. 



24. R. semistria'ta"*, Montagu. 



Turbo semistriatus, Mont. Test. Br. Suppl. p. 136. B. semistriata, F. & 

 H. iii. p. 117, pi. lxxx. f. 4, 7. 



Body pale-yellowish-white : pallial filament short : snout 



* Half-striated. 



