THE CUMACEA 



185 



When the lateral plates are removed, the conformation of the head 

 and the position of the eye show some similarity to the arrange- 

 ment met with in the Oedicerotidae ex 

 among the Amphipoda. The two eyes 

 are distinct in the embryo, and in one 

 genus (Nannastacus) also in the adult. 



Appendages. The antenmdes rarely 

 have both flagella well developed, the 

 inner being usually reduced or absent. 

 The antennae differ remarkably in the 

 two sexes. In the female (Fig. 112, a") 

 they are vestigial, while in the male they 

 consist of a stout peduncle of five seg- 

 ments, of which the last two are enlarged 

 and clothed with a brush of long setae, 

 while the flagellum is filiform and may 

 exceed the length of the body (Fig. 113). 

 In life this long flagellum is usually 

 carried folded close to the side of the 

 body, protected by the lower edge of the 

 carapace and by the pleural plates of the 

 abdomen, or in a special groove which 

 runs along the sides of the abdominal 



Fl - 112 



SOmiteS. In the genUS Lamprops the showing the internal organs, a', 



, a ,, e .1 i ' -IT antennule ; a", antenna; br, 



antennal flagella of the male are short branchial epipodite of tirst maxii- 



and stout, and are used as clasping-organs '^Sff^S^^^S. 



to hold the female. SfSSaSSZ fcS3g? 



I he mandibles never carry a palp, but spiratory siphon; /r, lateral 



in other respects conform to the type ? ^Sa'ST^S 



pVarartpri<5tiV of tViP Pprnparirla Tn tViP plate of pseudorostrum ; fc, heart ; 



eracanaa. in tne hep ^ hep c caec& . l a Hrst ^ r 



Leuconidae and in the genus Diastyloides of legs; ov, ovary; ps, pseudo- 



, , , , r , , , .?, . , , rostrum. (After Sars.) 



the body of the mandible is short and 



triangular and the row of spines is reduced. In Campylaspis the 



molar process is styliform. 



Fio. 113. 

 Pterocuma pectinat urn, <J, from the Caspian Sea. (After Sars, from Ency. Brit.) 



The maxillulae (Fig. 114, A), except in Platyaspis and Para- 

 lampraps, carry a retroverted palp as in Tanaidacea and Lopho- 

 gastridae. The maxillae (Fig. 114, B) with their two terminal 



