PELAGIC FLOATING CRUSTACEA 153 



consists in the division of each eye into two parts, 

 which differ in structure. In many Euphausiacea 

 and Mysidacea, especially in those haunting the 



FIG. 53 Copilia quadrata (FEMALE), A COPEPOD OF THE FAMILY 



CORYC^EID^E. SHOWING THE PAIR OF LARGE " TELESCOPIC " EYES. 



x 20. (After Giesbrecht.) 



deeper strata (mesoplankton), this division of the 

 eyes is well marked, a frontal or dorsal part having 

 the separate elements of the eye (ommatidia) greatly 



