134 The Shell-Collector’s Handbook. 
BALIA PERVERSA, LINN. 
SHELL sinistral, fusiform, turretted, transparent, glossy, 
yellowish horn-colour, streaked with white, irregularly 
striated ; whorls seven to eight, convex ; spire turretted, 
blunt, unstriated, polished; suture deepish; aperture 
rounded, pyriform, with sometimes a denticle near the 
middle of the base of the penultimate whorl; umbilical 
chink narrow. Length 93; diam. 22 mill.; ap. 22 mill. 
long, 13 wide. Animal dark brown, tinged with grey. 
Habitat.—Under the bark of old trees, and among the 
lichens growing upon them. 
v. viridula (Jeff.): Shell greenish-white, transparent. 
PBC; vol,.i., p. 274.) . 
v. simplex (Moqg.): Peristome without callosity, 
whitish. 
