THE DECAPODA 



261 



coiled to fit into the Gasteropod shells inhabited by the animals. 

 Only the sixth somite and the telson are fully calcified, the tergal 

 portions of the other somites being merely indicated by \vndely 



Fro. 151. 



Pijlo-lidex Mler^ii (Pagnndea). <>, eml view of tlie animal loflgeil in a tube of water-lo-ijcd 

 mangrove or bamboo, its cbolipeds closini; the opening. The lower li;,'ure shows the animal 

 in a conventional attitude after removal from its refuge. (From Alcock, NaturalUt in Indian 



separated chitinous plates in the membranous investment of the 

 dorsal surface. In the coco-nut crab Birgus (Coenobitidae) (Fig. 

 1.52), which has abandoned the tise of a covering for the hinder 

 part of the body, the abdomen, though short, is symmetrical 

 and its terga are well calcified. In the Lithodidae (Fig. 153), 



