THE COLOURS OF COWRIES 353 
more pronounced, and in a half-grown specimen of the 
same species is so elongated as to project considerably 
beyond the hinder extremity of the shell. Moreover, in 
immature examples of this species the hinder extremity 
of the right margin of the shell is expanded into a wing- 
like extension, recalling the wing-shells, or Strombzdae. 
In both the adult and the young of Scott’s cowry the 
coloration is very similar; but in the young of the Surinam- 
toad cowry there is a difference both in form and in 
colour from the adult. In form the shell has a distinct 
spire, and a thin outer lip; and in still younger examples 
these characters are more exaggerated, the mouth being 
entirely devoid of teeth, and the outer lip quite thin and 
sharp. Again, whereas the upper surface of the adult 
shell has a broad dark brown margin, and the central 
area spotted with light brown on a ground of dark 
brown, the young exhibits dark and light transverse bands, 
with a certain amount of mottling. 
Young cowries, then, are much more like ordinary shells 
than are the adults, and clearly indicate that the latter 
belong to a highly modified or specialised type. The 
alteration is produced by the expansion of the mantle- 
lobes of the adult, which deposit a shining enamel over 
the entire shell, eventually concealing more or less com- 
pletely the spire, and thus totally modifying the original 
form. A young cowry is, indeed, much more like an olive 
or a melon-shell; but, as a matter of fact, neither of the 
two latter are the nearest relatives of the Cypraezdae, among 
which are the Strombidae, or wing-shells. And in this 
connection the near resemblance of the young of Scott’s 
cowry to a wing-shell is decidedly worthy of note, as 
suggestive of a direct affinity between the wing-shells and 
the cowries. 
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