FAUNA AND FLORA OF THE SEA BOTTOM, 



1259 



Fig. 23. — Local distribution of Crepidula convexa. a smaller species than the preceding. The present species is most 

 frequently taken upon the shells of the small hermit crab, Pagurus longicarp^is. It is interesting to note, however, 

 that the distribution of the moUusk appears to be almost wholly restricted to the adlittoral zone, while that of the 

 crab is much more general (see fig. 26). 



