174 LAND AND FRESH-WATER MOLLUSKS. 
Genus Succinea {Amber Snails). 
The amber snails are so named because of the 
colour of the shells, which has some resemblance 
to that of succinum or amber ; they have a large 
body with a broad foot, with the tentacles short 
Fig. 23.—A transverse row of the lingual ribbon of S. putris (Loven). 
and thick, as shown in PL VI, fig. 44. The 
lingual teeth are like those of jHelix ; in S. putris , 
the formula is - 32 - 1 ' ~? the central tooth differs 
only from the laterals in size: the teeth are 
three-lobed, the central is large (see fig. 23). 
The shell is thin, oval or oblong, with a small 
spire and rapidly enlarging whorls, the aperture 
is large and obliquely oval. The oblong shape of 
the shell distinguishes it from those of the other 
members of the Family Helicidce , but allies it to 
those of Limnceidce, but separable from them by 
the absence of any oblique fold on the columella. 
They all inhabit damp places, and though 
thriving on the stems of plants growing in the 
water, yet they rarely enter that element. 
The most common and largest of the species is 
Succinea putris —{the Common Amber Snail) 
