540 



ZOOLOGY 



ECT. 



In the Brin-ln/in-fi, or true Crabs, we reach the highest degree of 

 specialisation known among the Crustacea. The cephalothorax 

 (Fig. 427 ) is always of great proportional breadth, and is frequently 

 much br< >nder than long. The abdomen, on the other hand is greatly 



FIG. 427. Cancer pagurus. A, <Wsul ; B, ventral aspect. ,i,it. 7, aiiteininle ; ant.2, antenna; 

 itlui.l, Hint.-!, '<''.,", :ili(lipinin:il .segments; .E 1 , eye-stalk ; LI, !.'>, legs; mxp.S, third maxilli- 

 pedes. (A, After Bell.) 



i (( 1 need, its sternal region is uncalcified, and it lies permanently 

 flexed in a groove on the very broad thoracic sterna, so as to be 

 i ill en quite hidden in a view from above. In correspondence with 

 this the pleopods arc much reduced, the male retaining only two 

 1 mil's as copulatory organs, the female four pairs for the attachment 



