16 . 
South Australian Shells. 
S .v. NAT., 
April 
Vol. XVt. 
10th, 1935. 
on the base, these latter are often spotted with red; granulations 
on base flattened; base convex, umbilical region narrowly impress- 
ed; aperture subrhomboidal; outer lip thin, smooth inside; colu- 
mella oblique, smooth, rounded, somewhat excavatelv flattened 
at its base from within, not toothed. Height 15, diam. 14 mm. 
Uncommon; beach, Guichen Bay, Point Sinclair 12 x 16 mm., 
and St. Francis Island; also Western Australia — Hopetoun, Es- 
perence, and Ellensbrook. Dredged — Beachport to Yankalilla 
Bay and Cape Borda, 9-130 fathoms. (Type locality — Dredged 
five to seven fathoms off Rhyll, Phillip Island, Western Port, 
Victoria). Has been wrongly identified as Trochus decor atus 
Philippi, which is a more acutely conical shell with flatter whorls 
and larger granules. The species is very variable. The colour 
ornament may be distinctly marked with distinct brown spots on 
a peripheral cariria, and brown dots on the basal spirals, and 
axial flames on the whorls; or the shell may be uniform cinnamon 
brown with inconspicuous dots on the periphery, and perhaps 
showing in the suture. The spirals may be broad, close to- 
gether, nearly flat and smooth, with a central incision as though 
about to divide, or they may be narrow and numerous; they may 
be more or less granular or tuberculate. The variations seem 
all to grade into one another. 
C. legrandi Teni son-Woods 1876 (1875) ( Zizyphinus ). PI. 
1, fig. 4. Straightly conical, imperforate, solid, rather thick; 
yellowish-flesh-colour; spiral riblets, numerous, smooth, altern- 
ately larger and smaller, about eight on the penultimate whorl, 
about fourteen on the base; spire conic, straight; suture scarce- 
ly visible except for a slightly wider cingulus above them; whorls 
about six, flat, the last angular, nearly flat beneath, shortly de- 
flexed at aperture; aperture rhomboidal, oblique, with two prom- 
inent riblets inside the upper lip, basal lip thickened, columella 
almost straight. Height 13, diam. 13 mm. Aperture (inside) 
6x6 mm. Dredged — Beachport, Cape Jaffa, Cape Borda, 7 
miles S.W. of Newland Head, Backstairs Passage — 17 to 200 
fathoms. (Type locality — Chappell Island, Bass Straits). A 
small smooth-nibbed form. Most examples have their sides 
quite straight, some have the whorls slightly concave, others 
slightly convex, and in one the whorls were feebly gradate. Some 
individuals have the brown ground colour and the spiral lira* 
a light purple. Flindersian deep water forms are more delicate 
in sculpture and formation. 
C. retiarium Hedley & May 1908. PI. 1, fig. 5. Retiarius, 
a gladiator furnished with a net, from a fancied resemblance of the 
sculpture jof the shell. Conical, subperforate, with sharply keeled 
periphery: , overlapping spire whorls and a flat base; colour un- 
cert s»ssn all spiral threads parted by wider interstices, seven 
