220 MOLLUSCA. 
and the basal emargination elongated into a decided canal, though 
the animal has no siphon. 
Figure 275, the operculum. 
BULLA PARALLELA (Gould). 
Testa parva, tenuis, cylindracea, lactea, anticé rotundata, postice conica, 
imperforata, longitudinaliter minutissime striata, ad verticem et ad 
basim strtis undulatis decussata: apertura angusta, deorsum dilatata ; 
columella callo haud appresso induta ; labro ultra spiram adscendente, 
tunc deorsum tntorta. 
Bulla parallela, Goutp; Proceed. Boston Soc. Nat. Hist., iii. 251. 
December 1847. 
SHELL small, thin, pellucid, milk-white, cylindrical, rounded at 
base, obtusely conical at summit, imperforate at apex; surface deli- 
cately marked with lines of growth, and these are crossed at the lower 
and upper third of the shell, by somewhat conspicuous, minutely 
flexuous, revolving lines. The aperture is narrow, widening down- 
wards; lip sharp, rising considerably above the apex of the spire, and 
at the same time inclining towards it, then turning downwards and 
entering the aperture by a twisted fold; at base it is rounded, and 
rises upon the columella in the shape of a thick callus, which is not 
appressed to the body of the shell. 
Length about half an inch; breadth one-fifth of an inch. 
Habitat unknown. 
Much smaller and thinner than B. solida, though striated at the 
ends like it, and having the same conformation of the lip. Its sides 
also are parallel and not bulging. 
Figures 267, 267 a, two views of the shell. 
Buia BirasciaTa, Martini and Chem., tab. 21, fig. 190, 191; 
Lister, Conch., tab. 1056, f. 8. B. ampulla, (var.) Lin. and Auct 
Sowersy, Thes. Conch., pl. 122, fig. 59. 
