THE COPEPODA 103 



SUB-ORDER 2. Podoplea, Giesbrecht. 



(Most of the following characters are subject to modification in parasitic 

 forms.) 



Last thoracic somite movably articulated with the preceding, and 

 firmly united with the first abdominal somite, which it resembles in size 

 and form. Last pair of thoracic feet vestigial in both sexes ; not 

 modified as copulatory organs in male. Both or neither of the antennules 

 geniculate in the male. Eggs generally carried in paired or unpaired 

 masses. Heart absent (except in Misophria}. Male reproductive system 

 usually paired. Free-living (rarely pelagic) or parasitic. 



TRIBE 1. ISOKERANDRIA, Giesbrecht. 



Swimming forms with antennules not geniculate in male, generally 

 similarly segmented in both sexes, and parasitic forms allied to these. 



Family CLAUSIDIIDAE. Clausidium, Kossmann. Family CORYCAEIDAE. 

 Corycaeus, Dana (Fig. 47); Copilia, v Dana ; Sapphirina, J. V. Thompson. 

 Family. OXCAEIDAE. Oncaea, Philippi. Family LICHOMOLGIDAE. Licho- 

 molgus, Thorell. Family ERGASILIDAE. Ergasilus, Nordmann. Family 

 BOMOLOCHIDAE. Bomolochus, Nordmann. Family CLAUSIIDAE. Clausia, 

 Claparede. Family NEREICOLIDAE. Nereicola, Keferstein. 



TRIBE 2. AMPHARTHRANDRIA, Giesbrecht. 



Swimming forms, with both antennules geniculate in male, generally 

 differently segmented in the two sexes, and parasitic forms allied to these. 



Family MISOPHRIIDAE. Misophria, Boeck. Family HARPACTICIDAE. 

 This extensive group corresponds rather to an assemblage of families (cf. 

 Sars) : Harpacticus, Milne-Edwards ; Longipedia, Glaus ; Cervinia, 

 Norman ; Ectinosoma, Boeck ; Peltidium, Philippi ; Tegastes, Norman ; 

 Porcellidium, Glaus ; Idya, Philippi ; Thalestris, Glaus ; Diosaccus, 

 Boeck ; Canthocamptus, AJJestwood ; Belisarius, Maupas ; Laophonte, 

 Philippi ; Kctelki, Dana ; Miracia, Dana ; Aegisthus, Giesbrecht ; Clytem- 

 n extra, Dana, Family CYCLOPIDAE. Cyclops, Muller ; Oithona, Baird. 

 Family MONSTRILLIDAE. Monstrilla, Dana ; Haemocera, Malaquin (Fig. 

 53). Family ASCIDICOLIDAE. Ascidicola, Thorell ; Notodelphys, Allman , 

 Doropygus, Thorell ; Notopterophorus, Costa ; Enterognathus, Giesbrecht 

 (Fig. 50). Family ASTEROCHERIDAE. Asterocheres, Boeck ; Acontio- 

 phorns, Brady (Fig. 44) ; Cancerilla, Dalyell ; Scottocheres, Giesbrecht ; 

 Artrotroyus, Boeck (Fig. 46). Family NICOTHOIDAE. Nicothoe, Audouin. 

 Family DICHELESTIIDAE. Dichelestium, Hermann ; Lernanthropus, 

 Nordmann. 



The position of the remaining families (consisting wholly of parasitic 

 forms) with respect to this system of classification is not yet determined. 

 The groups most usually accepted are : 



Family CALIGIDAE. Caligus, Miiller. Family LERNAEIDAE. Lernaea, 

 Linn. (Figs. 51, 52); Pennella, Oken ; Lernaeocera, Blainville. Family 

 LERNAEOPODIDAE. Lernaeopoda, Kroyer ; Achtheres, Nordmann (Fig. 

 45). Family CHONDRACANTHIDAE. Chondracanthus, La Roche. Family 



