ctata, spiraliter
sulcata, subgranulata, umbilico extus crenato.

Inhab. -- Mus. Brit.

Shell depressed, conical, pale reddish, ornamented with rows of white and
brown spots, spirally grooved, ribs slightly granulated; the sutures
distinct, impressed, the lower part of the last whorl nearly smooth, the
umbilicus white, smooth inside, the edge furnished with a series of
granules. The mouth subquadrangular, outer lip crenulated at the edge,
the columella lip smooth, with a large tooth at the inside, and a little
roughness on the outer side; axis three-tenths, diameter five-twelfths of
an inch.

31. Monodonta constricta, Lam. Hist. 7 36.

32. Monodonta rudis (n.s.)

Testa ovato-conica imperforata ulbido-purpurea rudis crassa, labro
duplicato, extus albido viridi, intus subsulcato, albo.

Inhab. -- Mus. Brit.

Shell ovate, conical, imperfurated, rough, pearly, concentrically
striated, whitish-brown; when worn or where eroded, purple; the whorls
convex, suture distinct, sometimes occupying an impressed line on the
lower whorl; the base rather convex, the aperture roundish, the axis
(imperforate) covered with a white callus, which leaves a slight
concavity over its end; the outer lip of three colours, the outer part
purple or green and white, the middle pearly, and the inner opaque,
white, and furrowed; the surface of the lower part of the last whorl is
frequently worn away just opposite the mouth, so as to leave a purple
spot.

33. Rissoa clathrata (n.s.)

Testa subglobosa, subimperforata, alba, solida, spiraliter et concentrice
costata; apertura suborbiculari, sutura impressa.

Shell nearly globular, spire conical, upper whorls with three, lower with
seven distinct, large, rather separate, much raised, spiral ribs, and
numerous acute transverse ribs, which form an acute tubercle where it
crosses the spiral ridges, the suture deeply impressed, very distinct,
the aperture nearly orbicular, the outer lip denticulated on its outer
edge, inner lip smooth, column without any perforation, only a slight
linear cavity behind the inner lip, axis and diameter each one-sixth of
an inch.

This shell is allied to Littorina muricata (Turbo muricata, Lin.) in its
general form and the shape of its umbilicus, but is white and ribbed like
Rissoa cimex (Turbo cimex, Lin.) R. calathriscus, the Turbo calathriscus
of Montague.

34. Solarium biangulatum (n.s.)

Testa orbiculato-conica subdepressa albida spiraliter sub-striata ruf