222 HELICIDJE. 



the frigid winds of winter, without attempting to de- 

 scend. It forms, however, a thin membranous epi- 

 phragm for its protection against such extremes of heat 

 and cold, and shelters itself in clefts of rocks and crevices 

 of walls. This little snail, in crawling, usually carries 

 its shell quite upright, and not inclined to one side like 

 most of its congeners. The upper whorls of the shell 

 are generally bleached by exposure of that part to the 

 sun. The animal is ovoviviparous, as well as that of 

 Pupa umbilicata ; and in specimens which I collected at 

 Kendal in the month of August, the fry in the interior 

 of the shell had a whorl and a half completely formed. 

 Moquin-Tandon counted in the matrix of several speci- 

 mens which he had received from Marseilles, from three 

 to seven young ones in each. It mostly frequents cal- 

 careous strata ; but in Germany it has been found on 

 felspathic rocks. It sometimes occurs in unusual places. 

 A specimen in my collection was taken by the trawl at 

 a depth of between twenty and thirty fathoms several 

 miles seaward of Plymouth, having been probably washed 

 down by a river or freshwater stream and transported 

 a long way before it sunk to the bottom. 



This is the H. umbilicata of Montagu; but as his 

 excellent work was published two years after Drapar- 

 naud's ' Tableau des Mollusques terrestres et fluviatiles 

 de la France,' my patriotic inclinations, however strong, 

 will not justify me in preferring the name given by my 

 countryman to the more ancient one of the French con- 

 chologist. The above-mentioned work of Draparnaud 

 does not appear to have been known to Dr. Gray when 

 he published an improved edition of Dr. Turton's ' Ma- 

 nual of British Land and Freshwater Shells.' The work 

 in question was published in 1801, Montagu's 'Testacea 

 Britannica ' in 1803, and Draparnaud's * Histoire natu- 



