164 LAND AND FRESH-WATER MOLLUSKS. 
narrow and triangular, in consequence of the 
great contraction of its outer edge in the middle. 
It is found about the roots of grass m marshy 
places in a few localities :—Singleton, near Swan- 
sea; Tenby; rejectamenta of the river Avon, at 
Bristol ; Battersea ; in Ireland, at Miltown Malby, 
co. Clare; Connemara, Galway; and at Cork. 
It occurs in Central Europe. 
GrEnus BALEA. 
The animal is bulimus-like ; the lingual ribbon 
is furnished with 130 rows of teeth, each row 
containing 50. ‘The shell is thin, slender, elon- 
gated, of many reversed whorls; the aperture is 
ovate, with the peristome thin, and sometimes 
furnished with an imperfect fold on the columella. 
The genus is intermediate between Pupa and 
Olausilia, but differs from the former in the 
shape of the aperture and the elongated spire, 
and from the latter in having no clausium. 
This generic group contains only a few species, 
one of which is indigenous to this country :— | 
BALEA PERVERSA—(the Fragile Moss Shell) (PI. 
IX., fig. 86).—The shell is oblong, slender, 
yellowish, transversely striated with seven or 
eight distinct whorls; the aperture is roundish, 
oval, and reversed ; the peristome is thin, and a 
little reflected on the columella, where there may 
