HELIX. 



229 



in search of food, and may iu the latter case be met with 

 in considerable numbers. The coloured streaks on the 

 shell somewhat resemble those on H. rotundata. Lister 

 first made the present species known, and says he had 

 often found it in woods in Lincolnshire. Linne gave it 

 the inappropriate name it now bears, from an erroneous 

 idea that it ate or excavated calcareous rocks, as the 

 Teredo does wood. This notion probably originated in 

 the surface of the shell being rough and like a file. His 

 H. albella appears to be the immature or younger state 

 of- the variety called by Menke albina. This white 

 variety has not been noticed as British ; but it is found 

 in Sweden and many other parts of the Continent. I 

 have taken it in Switzerland and the Lower Harz, with 

 specimens of the usual colour. The H. albella of Fleming 

 (Brit. Anim. p. 260) may also be the same state of this 

 variety. He found a single dead specimen on the shore 

 at St. Andrews in 1810. It is not at all likely that 

 Draparnaud^s species of that name (the H. explanata 

 of Miiller) would have found its way so far north ; and 

 Dr. Fleraing says that his shell diflPers from Drapar- 

 naud^s description. The H. Somershamiensis of Sheppard 

 (Linn. Trans, xiv. p. 159) is probably the young of the 

 present species. 



G. Shell flat or slightly concave above : outer lip thick and 

 furnished with a tooth-like tubercle : mnbilicus rather 

 large. 



24. H. obvolVta*, Miiller. 



H. obvoluta, Miill. Verm, Hist. pt. ii. p. 27 ; F. & H. iv. p. 63, pi. cxvii. 

 f. 1-3. 



Body narrow and somewhat truncate in front, brown with a 

 slight reddish tinge,, and speckled with milli-white in several 



* Wrapped-up. 



