TAB. CCCCXXVIIf .—figs 1 and 2. 
CIRRUS perspectivus. 
Spec. Char. Obtusely conical, spirally 
striated ; umbilicus deep, exposing one 
third of each whorl; aperture transversely 
oblong. 
Syn. Cirrus perspectivus, Mantell Geol . Sussex, 
p • 104 . lab . 18 . /. 12 and 21 . 
Not quite so high as wide, with a flattish base, in the 
centre of which is an acute conical umbilicus ; the in- 
ternal portion of each whorl is regularly convex ; the 
outer rather squared ; there is no canal around the 
spire ; the inner surface is pearly. 
Not uncommon in the upper Chalk of Sussex, Kent, 
Wiltshire &c. it is also found, but rarely, in the lower 
Chalk ; the place of the shell is often supplied by a 
green steatitic substance, that retains the cast of the 
external striated surface. The specimen (fig. 1.) shew- 
ing the internal pearly portion, is from Northfleet; the 
other was among a number sent from Wiltshire by the 
late Mr. Cunnington. 
Cirrus depressus. 
TAB. CCCCXXVIII .—Jig. 3. 
Spec. Char. Subdiscord, concentrically striated ; 
umbilicus wide, exposing a small portion of 
each whorl ; an angular canal runs round 
the spire; aperture obtusely angular. 
Syn. Cirrus depressus. Mantell GeoL Sussex , 
p . 195 . t . 18 ./. 18 and 22 . 
The short spire and the canal around it, produced by 
the prominent upper parts of the whorls, distinguish this 
from the last, it is nevertheless possible that they may 
be only varieties. 
Nearly as common as the C. perspectivus in the same 
situations, we have received it with a similar green coat- 
ing from Wiltshire; the specimen figured is from 
Bridgwick in Sussex, through the kindness of Gideon 
Mantell, Esq. 
