81 . 
S.A. NAT., VOL. XV. 
June 12th, 1934. By Bernard C. Cotton and F. K. Godfrey. 
limbatus is a well marked spiral lira, not gemmulated). Our 
shell may have nine lirae above the periphery (the ninth form¬ 
ing the periphery) and eleven below, or nine above and ten be¬ 
low, or eight above and eight, nine or ten below, or seven above 
and seven, eight or nine below, or six above and eight below. 
C. limbatus Quov Sc Gaimard 1834 ( Trochus ). 
(= Trochus morum Philippi 1848: = T. variegatus A. Adams 
1851, not Anton: not Q. brunneus A. Adams 1853, the Sydney 
shell). Depressed conoidal, carinate at periphery, umbilicate; 
whitish or yellowish, maculated with brown, generally with a 
series of blotches at periphery and beneath suture, the intervening 
space unicoloured or more or less tessellated; base tessellated or 
radiatelv flamed; sculptured above with six to eight spiral closely 
granulose cinguli, the interstices both above and below closely, 
sharply, microscopically striate; spire low, conical; protoconch 
acute, smooth; adult whorls four to five, convex just below the 
suture, then flattened, and at the periphery carinated; last whorl 
scarcely descending anteriorly; suture subcanaliculate; base slight¬ 
ly convex; aperture tetragonal, oblique; outer lip four or five 
lirate within, the upper fold somewhat enlarged, subdentiform; 
basal margin and marginal rib of umbilicus finely plicate; colu¬ 
mella oblique, nearly straight, its edge reflexed and plicate- 
dentate, terminating below in a small square denticle, inserted 
above upon the side of the umbilicus; umbilicus rather wide, 
funnel-shaped. Height 14, diam. 18 mm. Not uncommon on 
beach all round the coast of Southern Australia to Bunbury. 
Western Australia. Also dredged, alive to 40 fathoms, and dead 
to 200 fathoms. (Type locality'—Western Port, Victoria). 
The coarser granulation serves to separate this form from 
C. maxillatus Menke, and from C. unclatohles Tenison-Woods, 
a New South Wales shell. The reflexed crenulated edge of the 
columella is also characteristic. The basal margin of the aper¬ 
ture expanded in fully adult individuals. 
Two juveniles from Kingston show very plainly how with 
the increase in the size of the shell, the number of spirals in¬ 
creases by intercalation, first between the upper two rows of 
spirals, not counting the row of large infra-sutural nodules, and 
later between the lower two, so that the three rows are in¬ 
creased to five. On the base the outermost row is the finest 
and the nodules gradually increase towards the umbilicus. 
Measurements of Western Australian specimens, show those 
from Albany consistently the largest, height 13.5, diam. major 
22.25, minor .20 mm; the biggest from Bunbury being 10 x 14.5 
x 13 mm. 
