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 uniramous. Mandibles and maxillae 

 are present, and the first four thoracic segments bear biramous 



a.nt.2, 



s* 



7. Lernaea 



5. Lesheira 



6.T racheliasfes 



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



.s. egg-sac ; f.l, f.2, thoracic feet ; h, head ; M . male ; 

 (After Gerstaecker, Clans, Cuvier, and G. M. Thompson.) 



ant.2, antenna ; e. median eye ; e.s. egg-sac ; f.l, f.2, thoracic ff 

 mx.2. second maxillae; n, "neck." '*.**<* r>io,ic nin^ 



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. 



