298 MANUAL OF NATURAL HISTORY. 



and foot-jaws ; hind false-feet replaced by two mem- 

 branous filaments, not jointed. 



8. Family. — Tailed Grab-Lice (Ionidae). Body nar- 



row, elongated ; head large ; outer antennae 

 styliform ; abdominal appendages filiform, 

 and extending beyond abdomen; legs all 

 ending in sub-cheliform hands. Parasitic on 

 Callianassa. 



9. Family. — Tail-less Grab-Lice (Bopyridae). Body 



pyriform, depressed ; head inserted, rounded 

 in front ; antennae rudimentary ; abdominal 

 appendages lamellar, and concealed under 

 abdomen. 



III. LEGION. — Branchiopods (Branchiopoda). 



Mouth with organs of mastication ; no gills pro- 

 perly so called ; thoracic members foliaceous, mem- 

 branous, subservient to respiration. 



I. ORDER.— Phyllopods (Phyllopoda). 



Body naked, covered with a carapace, or enclosed 

 in a bivalve test ; legs, eight pairs, simple, natatory, 

 the rest foliaceous. 



1. Family. — NebaUas (Nebaliidae). Body enclosed 



in a bivalve test ; carapace beaked in front ; 

 eyes peduncled ; antennae large, forming na- 

 tatory oars ; four pairs of natatory non-bran- 

 chial feet, the rest branchial. 



2. Family. — Apuses (Apodidae). Carapace bivalve 



or scutiform ; all the feet branchial, consisting 



