574 



ZOOLOGY 



Cyclops (Fig. 451, 1) has been compared in form to a split pear, 

 the broad end being anterior, and the convex surface dorsal. 

 The first thoracic segment is fused with the head, and the 



anlf. 





2. Ca I o c a lanus 



Pig. 451. — Free-swimming Eucopepoda. la, female Cyclops, from the right side ; b, dorsal 

 view ; C, antenna of male ; 1), swimming-foot, abd.l, first abdominal segment ; ant.l, 

 antennule ; ant.S, antenna ; c th. cephalothorax ; e. median eye ; en. endopodite ; e.s. egg- 

 sac ; ex. exopodite ; ov. ovary ; pr.l, pr.2, protopodite ; r. rostrum ; .«..;• swimming-feet ; 

 th.%, th.6, thoracic segments. (After Huxley, Gerstaecker, Hartog, and Giesbrecht.) 



cephalothorax (c. th.) thus formed is covered with a carapace pro- 

 duced in front into a short spine or rostrum (r), near the base 

 of which, on the dorsal surface, is the median eye (e). There are 

 five free thoracic segments: the last (th. 6) bears the genital 



