80 DESCRIPTIONS. 
ground-colour of the shell, apex dark in some of the speci- 
mens, whorls somewhat rounded, smooth, granularly costate 
near the apex and deeply grooved at the base of the body- 
whorl, outer lip very thick, inner lip smooth in some of the 
specimens and lyrate in others, columella circumscribed, 
mostly smooth, Mauritius. 
Obs.—An elongated shell, allied to the last as well as to 
N. compta, succincta and pallidula, A. Ad. 
1105 N. quercina, Marrat.—-Shell somewhat acuminately-ovate, 
thick, ash-grey, marbled with fainter tints, whorls rounded, 
smooth, with the exception of the upper whorls of the spire 
which are costate, as is usual in almost every Nassa, columella 
smooth, curved, callous very thick, considerably expanded 
below,and continued up the body-whorl nearly to the sutural 
canal; outer lip thickened, forming a blunt edge to the 
border of the aperture, inner lip strongly plicate. 
Obs.—This is nearly allied to that very variable shell, 
N. corniculum, Olivi, and may be only a variety of it. 
778 N. granulosa, Marrat.—Shell elongately-conical, spire acumi- 
nated, pale buff, variegated with reddish brown, whorls 
convex, longitudinally ribbed and transversely grooved, 
granulated, with a beaded necklace. below the sutures, 
aperture oval, columella plicate, inner lip strongly lyrate, 
thin on the edge. 
Obs.—This shell clearly illustrates the tendency of all these 
forms to begin with the broadest and gradually to narrow into the 
most narrow and elongated varieties. I have a good series of the 
different varieties of form of the N. splendidula, Dunker, but this 
is far more bulimoid than any of the slender forms of that shell. 
768 N. lactea, Marrat.—Shell ovately-conical, white, apex pale 
purple, whorls rounded, costate throughout, ribs smooth, 
interstices closely grooved, coronated at the sutures, grooved 
below the beads, one of the ribs has a second bead below 
the first or sutural one. 
Obs.—Resembling the N. celata, A. Ad., and the N. rugosa, 
Marr.; it also shows an affinity with the N. fasciata, Lam., and the 
N. trivittata, Say. 
