TANAIDEA. gQ3 



seven joints to thorax'; six to abdomen ; segments very distinct, and 

 a little prominent, all transverse. Head of trapezoidal form. First 

 and second thoracic segments shorter than the following. Abdominal 

 stylets naked, the two forming a prolonged pointed termination to the 

 body. Inner antennae not seen in upper view, excepting the tuft of 

 hairs which projects at either corner of the head. Flagellum of outer 

 antennae very slender; joints slender, nearly naked. First pair of legs 

 minute ; second has a short and stout triangular hand, with the base 

 of the triangle set against the carpus; breadth less than length; 

 moveable finger at apex of hand, not half length of hand. Following 

 five pairs of legs similar; third and fourth pairs a little the stoutest; 

 claw slightly curved, half or two-thirds as long as preceding joint. 



Family II. BOPYRID^E. 



Subfamily IONINJE. 

 Genus ARGrEIA, Dana. 



Corporis articulationes uti in Bopyro. Appendices abdominis femince 

 non ramosos, vesiculiformes. TJiorax appendicibus branchialibus in- 

 structs . Abdomen maris appendicibus carens, non articulatum. 



Like Bopyrus in general form. Abdominal appendages quite simple 

 sacs. Thorax furnished with branchial appendages of similar form. 

 Male abdomen without appendages and not jointed. 



lone differs from this genus in having the female abdominal appen- 

 dages branched, and the male abdomen jointed and furnished with 

 appendages. The feet in the males are all similar, and terminate in a 

 small hand. The first thoracic segment is united to the head by a 

 separating suture. The following six segments are similar and free. 

 The abdomen is oval, pointed behind, and without any division into 

 segments. The female abdomen has six pairs of appendages, and each 



