262 MOLLUSCA. 
Nassa acinosa, Goutp; Proceed. Boston Soc. Nat. Hist., ii. 154. 
January 1850. Expedition Shells, 69. 
SuHett of medium size, rather thin, broad-ovate, apex acute, of an 
ashy-white, indistinctly banded with slate-colour. Surface decussated 
with sharp, longitudinal, and revolving ribs, about equally spaced 
each way, thus forming ranges of acute papille of uniform size, except 
the upper range, which is larger, three on the upper and eight on the 
lower whorl. Spire short conic, whorls seven or eight, the upper ones 
not convex, distinctly shouldered, the last one large and ventricose, 
comprising the greater part of the shell. Aperture one-half the length 
of the shell, small, narrow; lip thick behind, acute-edged, slightly 
arcuate, with five or six folds within; pillar strongly arcuate at the 
middle, with a prominent ]amina and distinct canal posteriorly ; callus 
thin, not appressed; the siphonal region is white and without a con- 
spicuous constriction: notch very ample; interior with a central and 
basal dark band. 
Length seven-tenths of an inch ; breadth two-fifths of an inch. 
Habitat unknown. 
Differs from the shell given by Kiener as young B. marginulatum 
by its more ventricose form, much coarser sculpture, less elongated 
spire, and the presence of the posterior lamina on the pillar. It may 
be compared with Bucc. Grunert, Dunker. 
Figures 329, 329 a, two views of the shell, enlarged ; 329 0, natural 
size. 
Nassa PAUPERA (Gould). 
T. parva, solida, ovato-lanceolata, albida lined rufa unica cincta, longi- 
trorsum octodecim-costulata, et liris continuis cincta: spira acuto- 
conica, anfractibus sex ad septem ventricosis, ultimo brevt, subgloboso ; 
sutura profunda: apertura parva, subcircularis, trientem longitudinis 
teste adequans ; labro arcuato, intus decem-striato ; columella anticé 
producta, callo granuloso haud appresso parce induta. 
