574 



ZOOLOGY 



SECT. 



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 



a.ni.f 



I.C y c I o b s 



2.Calocalanus 



Fie. 4'il. Free-swimming Euccpepoda. In, female Cyclops, from the right side; b, dorsal 

 view ; C, antenna of male ; I), swimming-foot, it/n/.l, first abdominal segment ; nnt.l, 

 antennule ; ant.2, antenna; c. th. eephalothorax ; c. median eye ; en. endopodite ; <'.. egg- 

 sac; ex. exopodite ; or. ovary; pr.l, pr.3, protopodite ; r. rostrum; s..f. swimming-feet; 

 t/t.%, th.G, thoracic segments. (After Huxley, Gerstaccker, Hartog, and Gicsbrecht.) 



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 (c). There are 

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



