THE CEUSTACEA 177 



very beautiful little crabs, with nearly quadrangular bodies 

 (set with the angles towards head and tail). They are 

 about half-an-inch across, and of a delicate pink colour. 



Our local species are Ebalia tuberosa, Ebalia tumifacta 

 and Ebalia cranchii the last-named rare. They are to 

 be found on shelly gravel and ' amid the " nullipore " 

 corallines at extremely low spring tides. 



The Pinnotheridce- ("Pea Crabs"). Two 'species of this 



Fig. 82. Inachus dorxettemis . Male, f Natural size 



curious little crustacean occur on our coast. They live in 

 a sort of commensal manner, within the shells of living 

 bivalve molluscs, nestling between the mantle and the gills. 



The most familiar example is Pinnotheres pisum. It is 

 frequently found in the oyster. 



The female is the larger, about the size of a good marrow- 

 fat pea. It is more frequently met with than the male, 

 as the latter is of roaming habit. 



M 



