75 
peripheral ridge pillar slightly covered by enamel 
forming an acute angle at junction with outer lip. 
Nacreous, colour chestnut brown, blotches. The 
inter-ridgial spaces are crossed by very distinct 
tine camellar lines of growth. Height 2 m., breadth 
4 m m. 
Solariellci approximates, A. Bell.—Shell small, spire depressed 
whorls 8—4 rounded at side, battened above with 
3—4 sharply moulded circular ridges, the peripheral 
one strongest. Of the 3—4 ridges below, the lowest 
2 are granulated by strong lines of growth Suture 
distinct. Umbilicus deep and open pillar and bare 
of outer lip obtusely angulated. Mouth obliquely 
stromboidal. Nacreous, much resembles a small 
Euomphalus pentangulatus. Height P2o m.m , breadth 
2 m.m. 
This and the preceding species belong to a group of Trochi characterised by the 
flatness of the top of the whorls, of which Trochus cinctus , Phil., Margarita maculata, 
S. V. Wood, and Trochus amabilis , Jeffreys, are the most pronounced forms. 
These, according to Dr. Jeffreys, are one and the same species. S, approximates, 
closely resembles the young of M. maculata for which 1 took it at first. It differs 
as far as I can see, judging by the few examples I have met with, from the latter 
shell by the greater depression of the spire and the angularity of the mouth. 
Cithna minima, A. Bell.— Shell a short conic oval. Whorls 4, 
angulated on the body whorl which comprises the 
greater part of the shell. Preceding whorls short, 
apex depressed ; suture deep, mouth almost circular, 
base expanded, pillar lip curved, canal or chink long 
and narrow. 
Hijclrobia compactilis, A. Bell —A smooth white solid shell; whorls 
5—fl. Apex blunt, two next whorls round and 
swollen, remainder turned, mouth roundly oval, outer 
lip thickened outside, inner lip thin slight, barely 
continuous ; base slightly effuse, imperforate. 
Somewhat resembles H. compcicta , Jeffreys, but differs in several points from 
that species. 
Rissoa deliciosa, Jeffreys.—Proc. Zool. Soc., Lond., 1884, p. 121, 
pi. ix., fig. 7. The only Selsey example cannot be 
separated from the above species with which it agrees 
in figure and description. 
Rissoa bicarinata, A. Bell. —Shell an elongated cone with bluntly 
pointed apex. Whorls (>, body whorl equalling all the 
others, flatly convex, suture deep, body whorl sharply 
angulated at the periphery, and less so below or on 
the shoulder producing a squarish outline, peristome 
continuous, outer lip strengthened by exterior rib, 
inner lip thin, chink small. 
Rissoa scutula, A. Bell.—Shell conic, apex blunt, whorls 6 —7, con¬ 
vex ornamented with close set long oval scute like 
markings depressed in the centre, the whole resembling 
the links of a chain, these do not pass below the 
periphery of body whorl. Outer lip rounded, 
thickened by an exterior varix, peristome continuous, 
inner lip slight, pillar nearly straight. Chink distinct 
but small ; base effuse. Length 3 m.m., breadth 1 
m.m. 
