GASTEROPODA. 179 
and all of them beaded by the passage of a regular series of bars 
across them, which, as they cross the interstices of the ribs, leave deep 
pits, and crenulate the outer edges of the external ribs; the third rib 
on the basal whorl forms an angle; the base is convex, with six fine, 
equal ribs, barred in a similar manner. Aperture small, subcircular ; 
columella straight, denticulated with four or five minute, unequal 
folds; interior pearly, with a regular series of thin, delicate, revolving 
ribs. 
Axis half an inch; diameter three-eighths of an inch. 
Dredged at Singapore. Pickering. 
This beautiful little conical shell is distinct from any described 
species. Its markings are deeply sculptured, and its peculiar sutural 
region is a character which cannot fail to be noticed at first glance. 
As it was obtained by the dredge, it is quite probable that it may be 
coloured differently when in the fresh state. 
Figure 216, the profile; and 216a, the base of the shell; 2164, 
216 c, details of the sculpture. 
TRrocuus actnosus (Gould). 
Testa solida, convexo-conica, eruginosa, seriebus quaternis papillarum 
insignis et ineolis capillacets volventibus ubique insculpta ; serie antica 
maori: spira anfractibus sex planiusculis. ultimo acutangulato : basis 
excavata, cinerea, filis concentricis fuscis cincta; interspatiis inden- 
tatis ; regione umbilicalt infundibultformi et costis duabus tri-partita: 
apertura rhombea; columella levi, contorta; labro simplici, perob- 
lquo. 
Trochus acinosus, Goud; Proceed. Boston Soc. Nat. Hist., iii. 92. 
March 1849. Expedition Shells, 57. 
SHELL rather small, solid, conical, with the outline of the profile a 
little convex; the base flat, concave, with a more distinct, central, 
tunnel-shaped pit, the walls of which are subdivided by two revolv- 
ing white ribs: whorls about six, nearly flat, each one having at the 
