GASTEROPODA. 151 
SHELL minute, fawn-coloured or pale ferruginous, elongated, acutely 
turreted, having about ten undulations on the upper whorls, which 
end on the middle of the last whorl; on each whorl are four delicate, 
raised, beaded, revolving lines, and on the anterior part of the basal 
whorl several other finer threads, some of which are usually beaded. 
There are several well-marked varices, the outer lip being fortified 
with a large one. Whorls about eight, convex, somewhat overhang- 
ing each other. Aperture broad ovate, oblique; rostral canal very 
short; columella arched, with a delicate coat of callus thickened at the 
posterior angle; suture deep. 
Length one-fifth of an inch; breadth one-twelfth of an inch. 
Inhabits the Sandwich Islands. 
A little shell, about the size and with many of the characters of C. 
Emersonu. It also resembles C. ferrugineum, Say, but is much 
smaller. 
Figure 172, front view of the shell, enlarged; 1724, natural size; 
172, details of sculpture. 
CERITHIUM EGENUM (Gould). 
Testa minuta, lanceolata, allida, ad basim maculis parvis fuscis notata: 
spira acuminata, anfractibus ad decem convexiusculis, filis ad quinque 
cinctis, quorum central et suturah majoribus, anfractu ultimo utrin- 
que varicoso: apertura rotundato-ovalis ; rostro brevissimo ; columella 
postice callosd. 
Cerithium egenum, GouLp; Proceed. Boston Soc. Nat. Hist., iii. 120. 
May 1849. Expedition Shells, 62. 
SHELL minute, dingy white, with a few minute, dusky blotches 
about the base, elongated, turreted, acuminate at apex; surface dead, 
indefinitely sculptured with about five indistinct, unequal, sharp, 
revolving lines, of which the sutural and central ones are largest. 
Whorls about ten, scarcely convex; a well-marked varix on the left 
side of the basal whorl; whorls rendered a little angular by the large 
