XI 



PHYLUM ARTHROPODA 



561 



peculiar form of joint and long setae as clasping organs, used 

 for holding the female during copulation. The antennae (ant. 2} 

 are comparatively short and uiiiramous. Mandibles and maxillae* 

 are present, and the first four thoracic segments bear biramous 



.TO 4-. Chondracanfhus 



C 3 



e-.s 



1. Lernaea 



5. Les I" e i r a 



G.Tr acheli a s r es 



FIG. 459. Various forms of parasitic Eucopepoda. 4a, female ; 4b, male, anl.l, antennule; 

 ant.2, antenna ; e. median eye ; e.s. egg-sac ; f.l, f.2, thoracic feet ; h, head; M. male ; 

 mx.2, second maxilkp ; w, " neck." (After Gerstaecker, Clans, Cuvier, ami G. M. Thompson.) 



swimming-feet (la, s.f.), those of the right and left sides being 

 connected by transverse plates or couplers. The fifth thoracic 

 segment bears a pair of vestigial limbs : the abdominal segments 

 are limbless. 



