MEANS OF DISPERSAL. 165 



flying overhead with twigs in their mouths. A living 

 specimen oiLimncBa truncatula~W\Q "ditch mud-shell " 

 of Gray's Turton — once found, as the reader will 

 remember, on the top of a church in Preston, had very 

 probably been carried there, as Mr. Heathcote suggests, 

 adhering to one of the sticks taken up by a jackdaw 

 building in the tower. Thrushes, red-wings, etc. — great 

 snail-eaters — as Mr. Cordeaux remarks to me, will carry 

 shells to considerable distances, and from being disturbed 

 or otherwise may sometimes drop them, or neglect 

 to break them against their favourite stones, and Mr. 

 Roberts, I hear, has actually seen a thrush drop a snail 

 while flying. Quite recently, I found- on a snow- 

 covered road in Lincolnshire — a hibernating snail, 

 Helix aspersa, which, having a pierced epiphragm, had 

 almost certainly been carried and dropped by a bird. 

 No stones on which shells had been broken were near, 

 but several were seen at some distance along the same 

 road. On being placed in tepid water the snail revived, 

 and crawled away. 



Operculate land-shells, it seems probable, may 

 occasionally be carried in the manner already suggested 

 for operculate pond-snails in chapter iv., namely by 

 closure of the operculum, so as to hold on to the toes of 

 insects, etc. As there mentioned, a land-shell has 

 been seen holding on to a humble-bee in this way. 

 The observation referred to was made in June, 

 1885, and recorded in the Field in that year.^ The 



' F.WT.," Humble-bee trapped by snail," " Field," Ixv. (1885), 

 P.S43. 



