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^ID^, 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 



