228 HELIOID^S. 



or dusky, speckled with milk-white : tentacles very long, dark- 

 grey with a slight tinge of yellow ; bulbs very short and 

 globular : foot narrow and rounded in front, broader and 

 keeled behind, its sides having a whitish border. 



SHELL depressed above and below, rather solid, nearly 

 opaque, not glossy, yellowish tinted with reddish-brown, and 

 irregularly streaked across the whorls with the latter colour, 

 marked with indistinct lines of growth, and finely shagreened, 

 like seal-skin : periphery strongly and sharply keeled : epi- 

 dermis rather thick : whorls 5, greatly compressed towards 

 the periphery, the last exceeding in size the rest of the shell 

 and somewhat dilated towards the mouth : spire very little 

 raised, point blunt : suture rather slight but distinct : mouth 

 obliquely oval, angulated above and below, with rather a 

 deep notch in the line of the keeled periphery : outer lip 

 white, thickened and reflected, forming a complete peristome, 

 abruptly and considerably inflected on both sides : umbilicus 

 rather large, exposing a great part of the whorls and all the 

 internal spire. L. 0'25. B. 0'65. 



Var. minor. Shell smaller and more deeply coloured. 



HABITAT : Moist rocks, woods, and other places in 

 many parts of England, from Went Vale, Yorkshire, to 

 Portland Island. This species does not appear to be 

 found in Wales, Scotland, or Ireland. It has been sup- 

 posed to be restricted to calcareous districts ; but Mr. 

 Reece has found it close to Worcester, and Capt. Bruce 

 Hutton at Linton in North Devon, in neither of which 

 places is there any limestone, chalk, or oolite. In a spe- 

 cimen now before me the whorls are twisted, like the sca- 

 lariform distortion of some kinds of Planorbis. This is 

 one of our upper tertiary fossils. Its foreign range extends 

 from Finland to Portugal ; and Aradas and Maggiore 

 are said to have found a single specimen in Catania. 



This is a rather hardy, but inactive, snail. \ During 

 the daytime it lies concealed in the crevices of rocks or 

 old walls and under the bark of trees ; but in the dusk 

 of the evening, or after a shower of rain, it sallies forth 



