51 



ISOPODA 



Asellus aquaticus. 



1. Dorsal view of the entire animal, examined in a watch-glass. Head; eyes; the seven free terga 

 of the thorax (the tergum of the ist thoracic segment is obsolete); single piece representing the 

 fused abdominal segments (the ist abdominal segment may perhaps be seen as a minute free ring) ; 

 ist antennae; the much longer 2nd antennae; the seven pairs of ambulatory limbs; the bifurcated 

 6th abdominal appendages. 



(In small and transparent specimens: alimentary canal; liver.) 



2. Ventral view. Abdominal appendages ; brood-pouch in female, formed by the oostegites, processes 

 of the thoracic appendages. 



