HELIX. 127 



and fallen branches of trees. This very variable and 

 common species is, according to the Rev. Revett 

 Sheppard, amphibious, being " frequently found some 

 feet below the surface of water, on stakes and piles, 

 which it ascends and descends at pleasure." As it is 

 an extremely irritable little creature it may perhaps 

 resort to this expedient for the purpose of cooling its 

 temper. Between the months of April and September 

 it lays about forty eggs, which are white, opaque, 

 and of a globular form ; the young are excluded in 

 from twenty to twenty-five days. 



Var. i. subrufa. Shell reddish-brown, and more solid, with 

 a strong labial rib, not uncommon in dry situations, B. C. 



Var. 2. albida. Shell thinner, white or colourless. In 

 osier-beds, as well as on the limestone at Kendal, B.C. Near 

 Birmingham (G. Sherriff Tye), near Ackworth, Yorkshire (C. 

 Ashford), J.C. 



Var. 3. conica. Shell smaller, spire more raised. Sandhills 

 near Swansea, B.C. 



Var. 4. nana. Shell much smaller, but with a strong labial 

 rib ; spire depressed. Freshwater, Isle of Wight (Metcalfe), 

 B.C. 



Var. 5. subglobosa. Shell more globular, and much thinner, 

 horn-colour or white ; umbilicus very small. Northumberland 

 and Durham (Alder), Hammersmith, Plymouth, Brocklesby, 

 Lincolnshire (J. G. J.), B.C. Lichfield (Rev. J. McMurtrie). 



12. H. SERI'CEA,* MtJLLER. PL, VIII. 



Body brownish, or yellowish-grey, with close-set tubercles ; 

 tentacles rather long, diverging at their base, of an iron-grey 

 colour ; upper pair rather thick at the base, finely granulated ; 

 bulbs much swollen, especially below ; lower tentacles paler 

 and more transparent than the upper pair ; foot somewhat 

 raised at the sides, broad, light yellowish-grey. 



* Silky. 



