146 
grown at the entrance to American River, Kangaroo Island, 
and 2 fragments eroded, in 40 fathoms off Beachport; also 
in the Great Australian Bight, alive, in 72 and 100 fathoms. 
When quite young, up to 25 mm. in length, the shell 
is thin, pyriform, with a depressed exsert spire, and uni- 
coloured yellow, the spire tinged with brown. Then dark 
brown spots and splashes up to 2 or 3 mm. in size appear 
over the anterior third or from the spire to the notch. At 
30 mm. the colour becomes light purplish-brown, with two 
obscure yellowish-white transverse bands about 2 mm. wide, 
with about two-fourths of the shell between them. At 
40 mm. the purplish tint is deeper and the spots are still 
discrete, or the whole dorsum may be clouded with spots of 
irregular shape and obscure margins running into or super- 
imposed on one another. At 50 mm. the spots may be nearly 
effaced, and besides the two pale cross bands the indistinct 
spots may be seen to form obscure interrupted dark mahogany 
transverse bands. At 65 mm. the shell has grown more 
globular, being 50 mm. wide and 40 mm. high; it is still 
very thin; the outer lip is inflected, slightly convex, 14 mm. 
wide, and edentulous; the dorsum may have about 6 trans- 
verse dark rusty mahogany bands. After this the labrum 
flattens through callous deposits at the latero-labral margin, 
and teeth appear along the labral edge and the opposite 
columellar margin. The labral teeth become more valid and 
extend slightly over the inferior surface. They seem very 
often to extend to the extreme outer border, but this is an 
illusion due to blackish-brown rays, which extend from. the 
border, and become narrow as they approach the teeth. 
These rays are absent from the columellar side, where round 
or oval spots are found. ‘The teeth on both sides of the 
aperture are white or nearly so; also the central part of the 
base as well, but this varies greatly in degree, in some cases 
the base is almost wholly dark brown. Asa rule the border- 
ing latero-basal callus is nearly black. It may extend in 
varying degrees over the dorsum, and in some examples the 
whole dorsal surface may be very dark, producing what is 
popularly known as ‘‘the black cowry.” 
Reeve’s variety B of G.—seatte from Port Lincoln was 
evidently the form which Gaskoin subsequently described as 
C. thersites. It is now degraded to a varietal position. 
C. friendii from Geographe Bay is a much narrower and 
lower shell than the South Australian C. thersites, and might 
properly be regarded as a different species, but for the Esper- 
ance shells, which relatively are broader and higher than 
the former, but not proportionately so broad and high as 
the latter. 

