232 HELICID^E. 



The difference between this genus and Helix is very 

 trifling. The tentacles in the present genus are rather 

 shorter, and there are also some minor points of ana- 

 tomical distinction. The shell of Bulimus has a longer 

 spire; but this is a comparative character, and the 

 degree of difference between the length of the spire in 

 Helix conica and the young of Bulimus ventricosus (Helix 

 Bulimoides of Moquin-Tandon) is scarcely appreciable. 

 It is not from the limited means of observation which 

 are afforded by a collection of the Mollusca in this or 

 any other particular country that a safe conclusion can 

 be arrived at with respect to the line of generic distinc- 

 tion ; and this is especially the case with the genus now 

 under consideration. There are only three British species 

 of Bulimus ; and one of them, which is by far the most 

 common of all (B. acutus\ has been restored by Moquin- 

 Tandon to the genus Helix. This species is included in 

 a section from which Leach constructed his genus 

 Elisma ; and it will be here described first, as forming a 

 passage from Helix to the present genus. 



The habits of the Bulimi are nearly the same as those 

 of the Helices. Our native species of Bulimus appear 

 to be exclusively herbivorous. They frequent open downs 

 and woods, and are rarely met with in the haunts of 

 men, though B. acutus infests gardens near the sea-coast, 

 being probably tempted by the more succulent pasture. 

 Their manner of oviposition, as well as the shape and 

 arrangement of the eggs, are similar to what has been 

 observed with respect to the typical genus, Helix. A 

 peculiarity of this genus is the tendency which some 

 exotic species have to a reversal of the spire, attended 

 with a change of position in some of the principal organs 

 of the body. In other land-shells this phenomenon is 

 more usual in genera or species than in varieties. 



