110 BOOK OF SPECIES. 
** Columella callous. 
B. ARCULARIA. Ovate-conic, ventricose, 
thick, ash-colour (sometimes zoned with pale 
fulvous); body-whorl turgid, crowned with sharp- 
ish tubercles, and grooved below; whorls flattened 
above, strongly plaited longitudinally, and grooved 
transversely ; lip crenated below, striated within, 
and the throat zoned with reddish brown, 14; 
the middle of the body-whorl is smooth. W. 
22. 40. 
B. cononATUM. Ovate-acute, thickish, smooth, 
but striated at the base, somewhat olive-coloured, 
with obscure bands, or sometimes entirely of a 
sallow white, with pure white longitudinal streaks ; 
upper margin of whorls tuberculated ; lip towards 
the bottom armed with spinous denticles; striated 
within. 1. W. 22. 41. 
B.GisBosuLuM. Ovate, back gibbous, smooth, 
whitish or olive; spire short, acute; callus ex- 
tremely large, edged with orange, and extending 
to the apex; lip smooth. 3. W. 22. 46. 
B. NERITEUM. Orbicular, flattened, smooth, 
tawny white, somewhat mottled ; pillar-lip obso- 
letely dilated, and thickened ; last whorl sub-an- 
gular; spire extremely obtuse; diam. 7. W. 22. 
48. 
EBURNA. 
Shell oval or elongated ; lip perfectly simple; aper- 
ture longitudinal, emarginate at base ; columella 
