PORCELLANID.E. 81 



nislied that in a few moments not one was to be seen ; till, 

 perhaps weeks afterwards, on cleaning out the tank, I have 

 found every one clinging fast to the under side of some 

 piece of stone that lay on the bottom. When I knew this, 

 I placed flattish stones so close to the glass sides that I 

 could look beneath them, and had the pleasure of finding 

 them occupied by the Broad-claws. The crevice formed by 

 the inclination of the stone to the bottom may be very nar- 

 row, and I am not sure but that the Crab likes it all the 

 better, for he is expressly formed for such a dwelling ; his 

 body is particularly flat, his legs move in the same plane, 

 and his claws, though large for his size, are remarkably flat 

 also, thinned out, as it were, to an edge ; so that the whole 

 animal has somewhat the appearance of having been crushed 

 flat by the pressure of the stone under which he lives. Here 

 then is a beautiful adaptation of structure to habit; but 

 there is more of the same kind. The Crabs are carnivorous, 

 and in general they are very active, wandering continually 

 in search of prey, which they seize, when observed, with 

 their claws. How is our little Broad-claw to live, clinging 

 fast to his cranny, which he forsakes not from one month's 

 end to another. Like the thrifty housewives of London, 

 who do not go to market, but have their bread, and meat, 



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