212 
LIMNiEAD^. 
tlons^ on the larger of which are often a few trans- 
verse striae, and all of them obscurely striate lon- 
gitudinally ; aperture narrow oval, not a third part 
as long as the spire, with the pillar spread and white, 
but not forming an umbilicus. 
It varies in the convexity of the volutions, and 
their number, as we have them from different waters 
with from six to nine. 
This animal, like the other species, but perhaps 
more frequently, forms a thick white internal rib to 
the outer lip, just within the edge. 
2. Amphipeplea Nihon. (Membrane Shell.) 
The animal very like LimncBus ; but the edge of 
the mantle is much extended, so as to cover 
(when the animal is expanded) the oval, very 
thin, nearly membranaceous, flexible shell, 
which, like Limnceus^ has a plait on the pillar 
lip ; its axis and part of the body whorl is 
covered with an expansion of the inner lip. 
In Amphipeplea the same arrangement of teeth 
prevails ; but the tubercle of the lateral teeth is even 
still larger, in proportion to its plate. 
Muller, Montagu, and Nilson give a good de- 
scription of this animal. Draparnaud considered 
the part of the mantle which is reflected over the 
shell to be a viscid coat. 
Captain Brown, apparently not aware of the prior 
name, has called this genus Lutea^ a name that is 
quite inadmissible. 
96. 1. Amphipeplea glutinosa. Glutinous Mem- 
brane Shell. — - Shell semiglobular, extremely 
