126 LIMNZEID-. 
downward thread is apparently kept in position by suction; 
the top of the thread ending in a flat circular expansion, 
with a slight depression in the centre, the whole resemb- 
ling the bottom and stem of a wineglass inverted. Up 
and down these threads the little animals delight to crawl, 
and when two meet, as frequently happens, a fierce com- 
bat often ensues, the antagonists striving to dislodge each 
other by remarkably violent jerks. 
Var. I. injfidta (Mog.). Much larger, more ventricose. 
Var. Il. cérta (/af.). Spire very short. 
Var. III. oblonga ( Jef). Spire produced. 
Var. IV. alvina ( Jef). Shell white. 
Subfamily.—LIMNAINE. 
Genus.—AMPHIPEPLEA JVilsson. 
Animal not contained wholly within the shell. 
A. GLUTINOSA (e/utinous) Bruguiére. Pl. VII., f. 1. 
Oval, globular, very thin and glossy, transparent, pale amber or 
greyish horn-colour, here and there striated in the line of growth, and 
faintly, but closely striated spirally ; zAorls 3 to 4, tumid; sfzre slightly 
produced ; sz¢zve deepish ; #zozth nearly oval, contracted above. The 
expansion of the mantle, which in young individuals covers the shell, 
places it in the sub-genus Amphipeplea. A. 14mm. B. 114mm. 
This is a very local species though abundant where it 
occurs. In England it is found at Sandwich, near Reading 
and Henley, Norwich, Hulland Reading, L. Windermere. 
dn Ireland it has been met with in King’s Co., Co. Down 
