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 



2.Caloca lanus 



Fio. 451. — Frec-swimmiiig Eucopepoda. la, female Cyclops, from the right side ;&, dorsal 

 view ; C, antenna of male ; D, swiinniing-foot. abd.l, first abdominal segment ; antl, 

 anteniiule ; ant.^, antenna; r. th. cephalothorax ; e. median eye ; en, endopodite ; e.s. egg 

 sac ; ax. exopodite ; ov. ovary ; ?ir.i, 7>/.5, protopodite ; r. rostrum ; ii,f. swimming-feet ; 

 tk.2, ih.G, tlioracie segments. (After Iluxley, Gerstaccker, Ilartog, and Giesbrecht.) 



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

 duced in front into a short spine or rodnmi fv ), near the base 

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

 five free thoracic segments : the last {th, 6) bears the genital 



