102 MOLLUSCA. 
The aperture barely touches the penultimate whorl, and has a simple 
lip. 
Length of axis half an inch; breadth three-fourths of an inch. 
Inhabits Upolu. Couthouy. 
This rather large species stands at the head of a small group of 
rude and very variable species from the Pacific Islands. They have 
a bony structure, are coarsely indented and striated spirally, the 
whorls are often almost disconnected, and the umbilicus is so large 
as on the whole to approximate Solarium. 
Figures 116, 116 a, two views of the shell. 
CycLosToMA STRIGATUM (Gould). 
Testa solida, orbiculato-conica, pallidé beryllina, supra costulis cingulata, 
infra sub-planulata, umblilico amplo et carina acuta impendente limi- 
talo perforata: spira anfractibus quinque convexis, sutura bene dis- 
cretis, ultimo prope aperturam despecto, feré disjuncto: apertura cir- 
cularis ; peristomate simplict, everso, acuto. 
Cyclostoma strigatum, Gouin ; Proceed. Boston Soc. Nat. Hist., il. 
204. March 1847. Expedition Shells, 38. 
Suet rather small, solid, globose-conical, of a greenish-white, or 
pale beryl colour ; the surface above is fluted with regularly disposed 
rib-like ridges, of which there are about six on the last whorl, 
with the intervening spaces concavely excavated and finely barred 
with the lines of growth. ‘There are about five convex, somewhat 
earinated whorls, separated by a well-defined suture ; and the last one, 
just before it reaches the aperture, becomes somewhat detached, and 
curves inwards towards the axis. The base is somewhat flattened 
and smooth, or very minutely striated spirally. The umbilicus is 
large and tunnel-shaped, margined by a sharp, overhanging carina. 
The aperture barely touches the penultimate whorl, has a simple, 
sharp, shightly expanding lip. The operculum is thin, horny. The 
young specimens differ much from the adult, in being almost discoidal, 
with the umbilicus nearly as large as the aperture. 

