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 aud 

 lips. The former is narrow aud extends the 

 whole length of the shell. Tho 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 

 Decently 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 bo 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- 

 bois. Perhaps this influence ot color has much 

 to do with the abundance or scarcity of many 

 other shells, and it should be carefully studied. 

 AVe 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 Californiea, Gray^ Fig. 5, 

 PI. V, is sometimes known as the Coffee-bean 

 Shell, and its size and appearance warrant this 



