THE MOLLUSCA—HEDLEY. 43] 
CreriTtHium mMAcuLOsUM, Mighels. 
Kobelt, Conch. Cab., “Cerithium,” 1895, p. 499, pl. xxxv., figs. 
Ley Lg, 
One dead shell from the lagoon beach. Also occurs at Hawaii. 
CERITHIUM ROSTRATUM, Sowerby. 
Tryon, op. cit., p. 130, pl. xxiii, figs. 90, 91. 
Three specimens from the lagoon beach. There are examples 
in this Museum from the New Hebrides; Pease observed it in 
Hawaii; Hugh Cuming at Marutea, Paumotus ; Brazier at San 
Christoval, Solomons; the ‘“Chevert” took it in Torres Straits, and 
Tryon gives it from Fiji. 
CERITHIUM OCEANICUM, Sp. nov. 
(Fig. 19). 
Shell rather elongate, almost truncate anteriorly. Colour 
uniform chocolate. Whorls eight, the upper biangulate, the last 
equal in length to the remainder. Sculpture: there are on the 
penultimate whorl (including varices) twenty low, rounded, longi- 
tudinal ribs, which crenulate the suture. These cross regularly 
from whorl to whorl, becoming fewer but proportionately stronger 
as they ascend the spire ; on the last whorl they 
become evanescent. Two spiral lines of granules 
descend the spire, appearing on the crest of each 
rib as a smooth boss. On the body whorl there 
are besides, beneath these, three spiral lines in 
which the beads have nearly fused into a smooth 
continuous ridge, the uppermost of these is some- 
times apparent in the spire as a super sutural 
fasciole. The whole surface of the shell except 
the beads, is covered by close, microscopic, raised 
spiral hair lines. Three, obliquely ascending, con- 
tinuous lines of varices mount the spire a third of 
a whorl apart. Aperture slightly oblique, semi- 
lunate ; anterior canal hardly more than a notch, Fig. 19. 
directed sideways; columella anteriorly truncated, 
externally wrinkled and curved downwards and outwards, inter- 
nally with a low ridge-tubercle, callus on body whorl medium ; 
outer lip strongly variced behind, edge sharp, notched by the 
major spiral sculpture, finely grooved within. Length 8, breadth 
4 mm. 
A single, perhaps not quite adult specimen from the lagoon beach. 
This shell seems to be a dwarf of the species which Sowerby 
has figured* as “Cerithium granosus, Kiener.” The shell which 
Kiener himself figurest so differs in contour, sculpture, size, 
* Sowerby—Thesaurus Conch. ii., 1855, pl. clxxxi., fig. 128, 124. 
+ Kiener—Coquilles Vivantes, Canaliferes i. (n.d.), pl. iv., fig. 5, p. 57. 
