46 



— Antennae I and II in males with long, multisegmented flagellum. 

 superfamily Phronimoidea 13. 



11. Body with thick integument. Mandibles with well-developed, three- 

 segmented palps. Coxal plates free. Pereopod I simple, II chelate; 



basal articles of pereopods V-VII ovally broadened 



VIII. Family Vibiliidae Dana. 



— Body with thin hyaline-transparent integument. Mandibles without 

 palps. Coxal plates fused with pereon, Pereopod I with weak sub- 

 chela, pereopod II simple, or both appendages with chela; basal arti- 

 cles of pereopods V-VII not enlarged 12. 



12. Large crustaceans (50-140 mm). Maxillipeds with free outer lobes. 

 Pereopods I and II chelate. Uropods II absent; endopodites of 



uropods I and III fused with basipodites 



IX. Family Cystisomatidae Will.-Suhm. 



— Crustaceans up to 30 mm in size. Outer and inner lobes of maxillipes 

 fused into single plate. Pereopods I with weak subchela, pereopods II 



simple. Uropods II well developed; rami of uropods free 



X. Family Paraphronimidae Bov. 



13. All pereopods simple, similar in structure. Mandibular palps absent 

 in both sexes XII. Family Dairellidae Bov. 



— Some pereopods with somewhat distinct chela or subchela. Mandibu- 

 lar palps present in both sexes or only in males 14. 



42 14. Uropods broad, unsegmented plates 



XrV. Family Phros inidae Dana. 



— Uropods with free rami 15. 



15. Pereopods V with subchela formed by highly enlarged 5th and claw- 

 like 6th articles XIII. Family Phronimidae Dana. 



— Pereopods V simple, or (genus Bougisia) with small subchela formed 

 by 6th and 7th articles XI. Family Hyperiidae Dana. 



16. Second article of pereopods VI enlarged and broadened, operculate; 

 all distal articles together much shorter than it and attached subter- 

 minally to inner surface of 2nd article 17. 



— Second article of pereopods VI may be enlarged but not operculate; 

 distal articles usually longer than it and always attached terminally 

 to its edge 18. 



17. Pereopods VII comprise 2nd and sometimes 1-2 rudimentary distal 



articles. Mouth cone short, broad, cylindrical 



XXII. Family Platyscelidae Bate. 



— Distal segments of pereopods VII may be reduced, but number not 



less than four. Mouth cone elongated, tapering 



XXIII. Family Parascelidae Bov. 



18. Body cylindrical; head round, not produced into long tapering ros- 

 trum anterior to eyes 19. 



