IMITATIVE COLORING. 
25 
and a worthy representative of the famous genus 
of Cowries. * The back of the shell is well shown 
by the artist. It is of chestnut brown, sur- 
rounded by a darker stripe which shades off into 
light brown and bluish white. The other side 
is almost wholly occupied by the aperture and 
lips. The former is narrow and extends the 
whole length of the shell. The lips are white 
and set with about 22 teeth on each side. In the 
adult shell, the spire is completely concealed by 
the whorls. It was formerly quite rare, but has 
recently been found in considerable numbers in 
the southern part of the State, living with the 
large mussel, Modiola modiolus, which it greatly 
resembles in color. With this circumstance, .Mr, 
R. E. C. Stearns illustrates and enforces the 
theory of the preserving effects of imitative color. 
Ordinarily, this shell would be a conspicuous 
object, and would quickly be taken by man or 
beast; when lying among the similar looking 
mussel shells, however, it is not easy to discover 
it, or distinguish it from its very different neigh- 
bors. Perhaps this influence ot color has much 
to do with the abundance or , scarcity of many 
other shells, and it should be carefully studied. 
We should ask, as we gather shells, u Do they 
resemble their surroundings in color or form, and 
does this resemblance tend to protect them?” 
The study of this subject may guide us to the 
proper place to search for shells whose color and 
form we know. 
The little Trivia Californica , Gray, Fig. 5, 
Pi. V, is sometimes known as the Coffee-bean 
Shell, and its size and appearance warrant this 
