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living in the shells of the common conch, Stroutbus gigas. In one of 

 these shells was found in August 1910 a pair of crabs, Porcdlana 

 sayana (Leach), living as commensals with the big hermit crab. These 

 small crabs were at once recognized as different in color markings and 

 one proved to be a female bearing eggs on the abdominal appendages 

 and the other a male. 



Fig. 1 u. 2. Photoqrajih of male and iemsAe Porcdlana sa ijana (Leachj taken with an 

 enlargement of two diameters. 



The general color of the shell of these crabs was yellowish red: 

 upon this ground color were scattered numerous round spots of creamy 

 white, each spot sharply circumscribed by a narrow line of red, much 

 darker than the background. The pattern thus produced suggested oil 

 drops iloating side by side or some physical arrangement of foam rather 

 uniform and symmetrical over the whole animal. 



The male differed from the female not only in the size and shape 



