220 THE CRUSTACEA 



Alcirona, Hansen ; Tachaea, Schiodte and Meinert. Sub-Family AKGA- 

 THONINAE. Argathona, Stebbing. Sub-Family BARYBROTINAE. BarybroU*, 

 Schiodte and Meinert. Sub -Family A EGINAE. Aeya, Leach ; Rodnela, 

 Leach. Sub-Family CYMOTHOINAE. Cymothoa, Fabricius; Ceratothoc, 

 Dana ; Meinertia, Stebbing ; Nerorila, Leach. Family SEROLIDAK. 

 Serolis, Leach. Family SPHAEROMIDAE. Sub-Family LIMNORIINAE. 

 Limnoria, Leach. Sub-Family SPHAEROMINAE. Sphaeromn, Latreille ; 

 Cymodoce, Leach ; Dynamene, Leach ; Campecopea, Leach ; Monolistra, 

 Gerstaecker ; Vireia, Dollfus ; Cassidina, H. Milne-Edwards ; Ancimts, 

 H. Milne -Ed wards. Sub-Family PLAKARTHRIINAE. Plakarthrium, 

 Chilton. 



SUB-ORDER 4. Valvifera, G. 0. Sars (1882). 



Abdominal somites more or less coalesced ; antennal peduncle of five 

 segments ; mouth-parts normal ; coxopodites of thoracic legs expanded 

 into coxal plates, rarely quite concealed beneath pleural plates ; first pair 

 of pleopods similar in the two sexes (except in Pscudidothea), second pair 

 present in female ; uropods lateral, opercular, folded inwards over pleo- 

 pods, exopodite vestigial or absent. 



Family IDOTEIDAE. Idotea, Fabricius ; Chiridotea, Harger ; Glyptonotus, 

 Eights. Family CHAETILIIDAE. Chaetilia, Dana. Family PSEUDIDO- 

 THEIDAE. Pseudidothea, Ohlin. Family HOLOGNATHIDAE. Holognathus, 

 G. M. Thomson. Family AMESOPODIDAE. Amesopous, Stebbing. Family 

 ARCTURIDAE (ASTACILLIDAE). Arcturtis, Latreille ; Astacilla, Cordiner ; 

 Anarcturus, zur Strassen. 



SUB-ORDER 5. Oniscoidea, G. 0. Sars (1882). 



Abdominal somites rarely coalesced ; antennules minute ; antennal 

 peduncle of five segments ; mouth-parts not suctorial, mandibles without 

 palp, maxillae reduced ; coxopodites of thoracic legs expanded into coxal 

 plates, usually completely coalesced with body, rarely defined by sutures ; 

 first pair of pleopods usually differing in the two sexes, sometimes absent, 

 second pair present in female ; uropods sub-terminal, generally biramous and 

 styliform ; terrestrial in habits, often with pseudo- tracheae in pleopods. 



Family LIGIIDAE. Liyia, Fabricius ; Ligidium, Brandt. Family 

 TRICHONISCIDAE. Trichoniscus, Brandt; Haplophthalmus, Schiodte. Family 

 TYLIDAE. Tylos, Audouin ; Helleria, von Ebner. Family ONISCIDAE. 

 Sub-Family SCYPHACINAE. Scijphax, Dana. Sub -Family ONISCINAE. 

 Oniscus, Linnaeus ; Porcellio, Latreille (Fig. 118). Sub-Family ARMADIL- 

 LIDINAE. Armadillidium, Brandt; Cubaris, Brandt (= Armadillo, 

 Latreille). 



SUB-ORDER 6. Epicaridea, Latreille (1831). 



Parasitic forms in which the adult females are greatly modified, often 

 asymmetrical, sometimes without appendages and without segmentation of 

 the body ; mouth-parts suctorial, with simple piercing mandibles, max- 

 illulae and maxillae vestigial or absent ; pleopods, when present, without 

 sexual modification ; uropods uniramous, very small, often absent late 



