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University of California Publications in Zoology [Vol. 23 



as I know, on rocky shores. This preference for a sandy bottom is correlated 

 with certain structural peculiarities and a group of habits which may be men- 

 tioned here on account of their bearing- on the methods of fishing. Observation 

 of the crab where accessible in shallow water and of the young in aquaria furnish 

 the following facts: The crabs may often be seen moving quietly along over the 



