Fig. 211. — Diagram of the dorsal surface of a King-Crab, to 

 show the head-shield carrying the central eyes (oc') and 

 the lateral eyes {oc), and corresponding to six segments 

 / to VI) ; also the posterior sliield, corresponding to 

 twelve segments {VII to XVIII), and the terminal post- 

 anal spine {PA), which is identical in position with the 

 scorpion's sting (see Figs, 210 and 213). 



284 



