THE NAUTILUS. 27 



grows, and sometimes Crepidula convexa whicli I found (juite 

 abundantly on Modulus floridanus, has the color and something of 

 the corrugation of that shell, so that at first glance it appears to be 

 merely a patch. 



What is the object of this singular species of imitation? I believe 

 without exception it is a means of protection against the rapacitv of 

 boring molluscs ; one of the tricks which nature is constantly exhibit- 

 ing by which the " survival of the fittest " is attained. The shells of 

 the young oyster on the Cerithium, the Crepidula convexa on the 

 Modulus, the Anomias and Crejiidulas on the Pectens, were in every 

 case thinner than those on which they grew, hence more liable to be 

 pierced by carniverous molluscs — but by imitating the shells on 

 which they lived they stood a better chance of deceiving their ene- 

 mies, a better chance of self-preservation. Does this not look 

 almost like intelligence, almost akin to what we call thought in man 

 — like reason ; like studying from cause to effect? and I believe that 

 such variation as this is often perhaps one of the first steps towards 

 the formation of a new variety, a variation which if continued by 

 circumstances fixes certain characters that define a species, and 

 that these characters remain permanently — often after the causes 

 which produced them have passed away. 



LIST OF SHELLS OF THE NEW JERSEY COAST SOUTH OF 

 BRIGANTINE ISLAND. 



BY JOHN FORD. 



Ed. Nautilus, Dear Sir: 



As a list of the species of Mollusks found on the coast of 

 New Jersey, South of Brigantine Island, may be of interest to your 

 readers, I take the liberty of sending it. 



If any others can be added it would be a pleasure to hear 

 of them. 



Yours truly, 



John Ford. 

 Phila. June 15th, 1889. 



Anomia ephippium, Linn. 

 Area pexata, Say. 

 Area ponderosa, Say. (Fossil.) 

 Area transversa. Say 



