260 MOLLUSCA. 
Nassa cinctella, Goutp; Proceed. Boston Soc. Nat. Hist., iii. 154. 
January 1850. Expedition Shells, 69. 
SHELL minute, solid, shining, short ovate-conic, apex entire, yel- 
lowish-white, with a single brown thread on the middle of the last 
whorl, which appears along the suture on the other whorls; lip pur- 
plish. Surface with distant, elevated, somewhat compressed longitu- 
dinal rib-folds, about ten on the last whorl, reaching to the siphonal 
constriction, which is well-marked; these are crossed by crowded, im- 
pressed lines, about eight on the penultimate whorl, the one around 
the middle of the last whorl, which is coloured, being a little more 
prominent than the rest, causing the whorl to be a little angular. 
Spire conical, whorls about seven, flat, decidedly shouldered above, the 
last two-thirds the length of the shell, subglobose. Aperture less than 
one-half the length of the shell, small, oval; outer lip much thickened 
externally, crenulated by the revolving lines, with seven or eight pro- 
minent sulci within ; columella with a prominent, posterior lamina, and 
minute corrugations in front; callus not copious, not appressed ; inte- 
rior white (or perhaps croceous), the dark vitta appearing within. 
Length seven-tweutieths of an inch; breadth one-fifth of an inch. 
From the Pacific Islands. 
This very pretty shell is well marked by its short, conical form, its 
few prominent ribs, shouldered whorls, and thread-like vitta. It 
accords well with Bucc. Jonasit, Dunker, except that one of the prin- 
cipal characters of that shell is to have the interior of the lp smooth. 
Figures 327, 327 a, two views of the shell, enlarged; 327 4, natural 
sIze. 
Nassa casta (Gould). 
Testa tenuis, lanceolata, vitrea, alba fuscis rubiginosis binis cincta, 
longitrorsum costato-plicata ; plicis ad quatuordecim, striis remotis vol- 
ventibus decussantibus: spira acuto-conica, anfractibus octo convexius- 
culis, apicalibus politis, ultimo quadrantes tres longitudinis testa fere 
