66 SKENEID.E. 



7 or 8 obliquely striated turns, the last of which is propor- 

 tionally much the largest ; the under side has a small boss or 

 nipple-shaped point in the centre. L. 0-03. B. 0-06. 



Yar. 1. trochiformis. Spire more prominent, and umbilicus 

 consequently contracted. 



Var. 2. maculata. Yellowish-white ; the last whorl spirally 

 ornamented by a double row of circular reddish-brown spots, 

 one above and the other below the periphery. 



Yar. 3. Jiyalina. Clear- white and transparent. 



Habitat : Plentiful under stones and on seaweeds 

 between tide-marks all round the coast. Var. 1. Shet- 

 land, Skye, and Lough Larne ; this seems to bear the 

 same relation to the common form as the Helix rupes- 

 tris of Studer and Draparnaud does to the H umbilicata 

 of Montagu. Var. 2. Channel Isles. Var. 3. Skye and 

 Channel Isles. Fossil : Clyde beds (Smith and Cross- 

 key); Fort William (J. G. J.); post-glacial and glacial 

 beds in Norway, 130-380 feet (Sars). Recent : Spitz- 

 bergen (Torell) ; Iceland (Steenstrup and Torell) ; Scan- 

 dinavia (Loven and others) ; north of France (Mace, 

 Cailliaud and J. G. J.); Cannes (Mace); Nice (Ve- 

 rany); Spezzia (J. G. J.); Madeira (Johnson, fide Han- 

 ley) ; Greenland (Fabricius and Moller) ; Massachusetts 

 (Gould, as S. serpuloides) ; from Cape Cod northwards 

 (Stimpson) . Although it is a sublittoral species, Malm 

 has dredged it in 10 f. on the Swedish coast, and M f An- 

 drew in 15-4-0 f. on that of Upper Norway. 



This little mollusk feeds upon Lichina pygmcea and 

 small Conferva . It swims with facility in an inverted 

 posture, and occasionally suspends itself in the water by 

 spinning a viscous thread with its foot. When crawl- 

 ing, the shell is carried sideways, not erect. Mediter- 

 ranean specimens are frequently spotted, like our 2nd 

 variety. 



It is the Helix depressa of Montagu. 



