DESCRIPTIONS. 81 
N. decorata, Marrat.—Shell ovately-conical, whorls convex, 
longitudinally ribbed and strongly noduled, white, banded 
with brown, sutures somewhat canaliculated, aperture oval, 
columella wrinkled, outer lip thick, white, interior plicate, 
the last whorl angular at the base. 
Obs.—These very small shells may prove to be a variety of 
some other species; but if so, they have taken a very peculiar and 
abnormal form. 
571 N. grata, Marrat.—Shell ovately-conical, greyish-ash banded 
with brown, whorls rounded, strongly ribbed, interstices 
closely and deeply grooved, sutures noduled, the first forming 
the thickened lip large, aperture oval, columella thin, a 
little expanded, warty, outer lip thick, white, inner lip in 
some of the specimens almost smooth, in others with few 
and distant strong folds, crenated, toothed at the base. Canton. 
Obs.—I have no doubt that this shell will prove to be one of 
the connecting links between N. marginulata, Lam., and the N. 
Wilsoni, Reeve (not C. B. Adams.) Another variety, twice the size 
of the shells described, has been shown to me by Mr. Archer, it is 
from the Gulf of Siam. 
1307 N. cerulea, Marrat.—Shell ovately-elongated, greyish-ash, 
banded with blue, polished, whorls rounded, longitudinally 
finely striated, sutures closed, aperture oval, columella 
strongly wrinkled, callous thickened, somewhat spreading, 
outer lip thick, interior toothed. 
Obs. —This shell, whieh is about the size and nearly the colour 
of N. glabrata, A. Ad., is not distantly related to the N. trifasciata, 
Gmel.; it is also closely allied to the N. planicostata, A. Ad., and to 
some of the varieties of N. corniculum, Olivi; operculum crenated. 
1244 N. tabescens, Marrat.—Shell ovately-conical, white, banded 
with brown, whorls rounded, strongly ribbed, ribs smooth, 
interstices closely grooved ; the body-whorl has the ribs close 
and numerous, the penult-whorl has not more than half as 
many, the third has very few ; this may arise from some de- 
fect in the animal ; aperture oval, columella plicate, callous 
thin, outer lip thick, grooved, 
