86 trtjncatellidjE. 



Laskey says that lie dredged it off Dunbar, Fleming 

 that he found a specimen in the cavity of a dead Spa- 

 tangus purpureus from the Firth of Forth, Macgillivray 

 that it has been taken in sea-sand from Cruden in the 

 Moray Firth, and Thompson that Mrs. Hancock obtained 

 a young shell of this species at Bundoran in co. Donegal ; 

 Bean enumerates it in his list of Scarborough shells. 

 I suspect that there has been some mistake as to the 

 specimens from all these last five places. A large West- 

 Indian species (T. succinea, C. B. Adams) has been 

 often mistaken for ours. Philippi records the present 

 species as fossil in Sicily ; and I found specimens in a 

 quaternary or more recent deposit near Martigues in 

 the Departement of Bouches-du- Rhone. It inhabits the 

 Atlantic shores of France, both sides of the Mediter- 

 ranean, as well as the Adriatic and iEgean seas ; and 

 M.' Andrew has noticed it at Malaga and Lancerote. 



It creeps slowly, in the fashion of a caterpillar. The 

 action of the foot is thus described by Clark : — ' ' on the 

 march maintaining posteally and anteally the oval con- 

 tour, with a vermicular motion, like an advance of one 

 half to the other ; this action gives an apparent crease, 

 simulating an incised transverse line, but on the step 

 being completed, the foot becomes entire." I could not 

 detect any pulsation : the gill-pouch was transparent, 

 and appeared to be filled with air. The shell varies 

 considerably in bulk. Possibly the smooth kind, which 

 is smaller than the other, may be the male, and the 

 ribbed kind the female; the transition from one kind 

 to the other, however, is very gradual. 



Helix subcylindrica of Linne may be this species ; 

 but " Habitat in aquis dulcibus Europse borealis " makes 

 it rather doubtful. Montagu called the adult shell 

 Turbo truncatus, and the young T. subtruncatus ; Risso 



