ANCYLUS. 135 
This is a local species often plentiful where it occurs, 
inhabiting ponds and ditches in Great Britain, as far as 
Lanark ; in Ireland it is recorded for Cork and Belfast. 
For its frequent association with A. hypuorum and P. 
spirorbis see the former species. 
It is, like the preceding species, amphibious. I have 
often found it crawling up the stalks of reeds several 
inches out of water. Some that I once kept in an 
aquarium persisted in crawling up the glass side and 
tumbled out, thus falling victims to their adventurous 
disposition. 
Var. I. elongéta ( Jef.). Spire produced. 
Varo II) \zedjor (Gass.). Much larger, A. 23 mm: 
Monst. decollétum (Velson). Spire truncated. 
Subfamily.—ANCYLINE. 
Genus.—ANCYLUS Geoffroy. 
Shel/ limpet-shaped with a rudimentary spire which is dextral; its 
recurved form gives the name to the genus. 
A. FLUVIATILIS (zhabtting rivers) Miller. Pl. VII., f. 9. 
Shaped like the common marine limpet ; a@fex recurved. A. 7§ mm. 
B. 54 mm. 
The ‘Stream Limpet’ is found adhering to stones or 
wooden piles in streams and canals,—very rarely in still 
water. I have found it in ponds occasionally, but these 
cannot be regarded as a natural habitat. It is common 
