3S6 



ARTlIROrODA 



In the terrestrial species the gills are adapted for breathin,!:; damp air. In 

 rLVa-llio and ArmadiUiditni the ti'rst or first and second opercula are ].ermeated 

 with a system of air tulies, which physiologically, though not morphologically, 

 are comparable to the trachea; of insects. 



In the Isopoda the tendency to parasitism is greater than in the Aniphipoda. 

 Many swimming forms attach themselves to fishes and feed by boring with 

 their' modified mouth ]iarts into the skin. The Bopyrid;i; live in the branchial 

 chamber of shrimps. Crvptoiiisciis is a shapeless sac which attaches itself to the 

 stalk oiSaa-uIina (\x 374), and, after causing the death of this parasite, uses its 

 network of 'roots' t'or its own nourishment. The Entoniscidx (fig. 413) 

 attack Decapoda and, pressing the skin before them, penetrate the inte- 

 rior. Their strange shape is 'largely due to the lobe-like brood lamellT. 

 Thev are usually hermaphroditic, but have besides compleniental dwarf males 



(fig.'4i3>-I)- 



Fig. 



414. — .1, Idotca Irrorata*; B, Limnoria Ili^iioniiii*; C, JEgt 

 P,Lcl>loiln-I<i tilgicolii* (^aftcr Ilargcr). 



psora* ('salve bug'); 



Sub Order I. ANISOPOD.V. Si.\ free thoracic segments; heart thoracic; 

 first thoracic foot (on head) chelate; abdomen with swimming feet; intermediate 

 between Amphipoda and other Isopoda. Tuiiais,'^ Li'plcHhcla'^ (fig. 414). Sub 

 Order II. EUISOPOD.V. Seven free thoracic segments. On'iscid.e; terres- 

 trial, 'sow bugs'; Porccllio,'''' ihiisciis,''^ Armadilliditm* 'pill bug.' Asellid.E 

 (fig. 412), fresh water. Si'II-Eroiiid.e, head broail, body rounded and conye.x; 

 Sphccroma* Liiimoria lii^iioriiin'^' (fig. 414), gribble, destructive to submerged 

 wood. Idoticid.e, free-living, marine, with usually elongate bodies; Idotca* 

 Cacidotca* BopyRiD.E, parasitic on Caridea; boily of female disc-like, asym- 

 metrical, without eyes; Bopvrus* OvmothoiD-E, ]iarasilic on fishes or in their 

 mouths. Cyinolhoa* .E,t;a* Cirolana* Sub Order III. ENTONISCIDA, 

 general features are described above. Enloniscus. 



