184 LIFE BY THE SEASHORE. 



genus Pagurus, often divided into a number of sub-genera ; 

 it will be sufficient for us to consider the British species as 

 belonging to Pagurus itself, although they strictly fall into 

 the sub-genus Eupagurus. 



On the East Coast there is only one common species near 

 the shore, and that is P. bernhardus, or Bernard the Hermit, 

 as it is commonly called abroad. Of this form small 

 specimens are abundant, often extraordinarily abundant, in 

 all shore pools. In the Firth of Forth after storms the 

 beach is sometimes literally paved with hermits, and every 



FIG. 53. Common hermit-crab (Pagurus bernhardus) in the shell of the whelk, 



rock pool has its representatives. These inshore forms 

 inhabit the shells of the different species of periwinkle, 

 Trochm, Purpura, and of the smaller whelks, often much 

 damaged specimens the broken top of a very large 

 "buckie" seems indeed to arouse specially keen competi- 

 tion. The size of the hermits depends upon that of their 

 habitation, for the hermit changes its shell as it grows, so 

 that all these specimens are necessarily small ; the fact that 

 many of them will be found to be carrying eggs shows, 

 however, that maturity does not depend on size alone. 

 When removed from their shells it will be seen that all 

 these forms have an abdomen of blue colour. With these 



