BULIMUS. 235 



the hills above Whitsand Bay in Cornwall, without de- 

 vouring a prodigious quantity of snails, especially in the 

 night, or after rain, when they ascend the stunted blades." 

 The summer epiphragm is very thin, transparent, and 

 iridescent ; and it has a small hole in it, which corre- 

 sponds with the position of the respiratory orifice, thus 

 enabling the snail to procure fresh air without exposing 

 its body to the heat of the sun. The winter epi- 

 phragm is thicker, opaque, and yellowish, like paper. 

 Geologists can have some idea of the way in which land- 

 shells are accumulated and form tolerably thick strata, 

 from the fact recorded by Montagu, that the drifted sand 

 at Bigberry Bay in the South of Devon is full of dead 

 shells of the present species, to the depth of four feet. 



This is the Turbo fasciatus of Pennant and Montagu. 



The B. articulatus of Turton (the typical specimen of 

 which is in my collection) is an exotic shell, and not 

 Lamarck's species of that name, which is only a variety 

 of B. acutua. 



B. Shell oblong : spire blunt : outer lip thickened and 

 reflected. 



2. B. MONTA'NUS*, Draparnaud. 



B. montanus, Drap. Tabl. Moll. p. 65. B. Lackhamensis, F. &. H. 

 iv. p. 89, pi. cxxviii. f. 6. 



BODY rather thick, rounded in front, narrowing gradually 

 and pointed behind, dark-red or greyish-brown; tubercles 

 flattened, with very fine black points : mantle indistinctly 

 and minutely speckled with milk-white and brown : tentacles 

 somewhat thick and conical ; upper pair coarsely shagreened, 

 with thick and rather globular bulbs ; lower pair nearly 

 smooth, of a somewhat darker colour than the others : foot 

 truncate in front and ending in a long but blunt tail. 



SHELL conic-oblong, nearly semitransparent, rather glossy, 

 * Inhabiting mountains. 



