72 BRITISH MOLLUSKS. 



Helieella ericetorum, Risso (1826), Hist. Nat. 'Europ. 31erid. vol. iv. p. 7. 



Zonites ericetorum, Leach (1831), Turt. Man. p. 101. 



Oxychilus ericetorum, Fitzinger (1833), Syst. Yerz. p. 100. 



Thela ericetorum, Beck (1837), Ind. Moll. p. 13. 



Xerophila ericetorum, Held (1837), Isis, p. 913. 



Helix arenosa, Ziegler (1838), Rossm. Icon. vol. vii. p. 34. f. 119. 



Helix (Helieella) ericetorum,, Moquin-Tandon (1855), Hist. Moll. vol. ii. 

 p. 252. pi. xviii. f. 30 to 33. 



Hah. Central and Southern Europe. Nearly throughout Britain. (Princi- 

 pally on heaths and downs near the sea.) 



The well-known Heath Snail may be recognized by the depressed 

 subdiscoidal form and large umbilicus of the shell, the whorls being 

 narrow and widely tubularly convoluted. The painting appears in 

 bands and pencillings of semitransparent brown above the peri- 

 phery upon a buff-tinted ground. H. ericetorum is as abundant and 

 has much the same habit as H. virgata. It is more essentially a 

 southern species affecting a calcareous soil. After a shower of rain, 

 it may be seen by myriads attached to blades of grass on the downs 

 and roadside pastures near the sea ; but plentiful as they are in 

 Europe, neither species has been transplanted to the United States, 

 nor have they any representative species in that country. Out of 

 from sixty to seventy Helices indigenous to the United States, there 

 are only two with banded or variegated shells, H alternata and 

 Cumberlandiana, and these are of quite a distinct pattern. 



M. Moquin-Tandon gives some interesting particulars of the 

 anatomy and habits of H. ericetorum. It is, he says, a shy, inac- 

 tive mollusk, withdrawing itself on the slightest touch into its 

 shell, which is carried inclined while crawling. The epiphragm is 

 more or less painted, very thin and transparent, iridescent and 

 membranous, but it has a small calcareous spot upon it of the 

 size of the respiratory orifice. Lister stated, and Mr. Jeffreys cor- 

 roborates the statement, that continued rain kills H. ericetorum in 

 numbers. 



Linnseus named this species Helix Itala. The original type, in 

 the collection of the Linnean Society of London, has the figures 598, 

 referring to the number of the species in the ' Sy sterna Naturae,' 

 still remaining upon it in Linnseus's handwriting. But it was 

 known in this country nearly a century before by the name of 

 ericetorum, which has ever since been universally adopted. 



