45 



3. Pereon in females spherically bulging, in males scinoid. Mandibles 

 with narrow cutting edge; 3rd article of long thin palp longer than 

 its 1st and 2nd articles together. Superfamily Archaeoscinoidea. . . 

 I. Family Archaeoscinidae Barnard. 



— Pereon in females varies in shape but differs less than that in 

 males. Mandibles with broad or narrow cutting edge, usually 

 with strong three-articled palp, in which 3rd article shorter than 

 2nd; if palp absent, cutting edge of mandibles broad. Superfamily 

 Lanceoloidea 4. 



4. Mandibular palp present 5. 



— Mandibular palp absent III. Family Chuneolidae Wolt. 



5. Pereopods V-VII with retractile claws. Rarely {Lanceola falsa), claws 

 not greatly extended. Pereon usually bulging, but even in females not 

 spherical II. Family Lanceolidae Bov. 



41 — Pereopods V-VII with nonretractile claws. Pereon in females spher- 

 ical IV. Family Microphasmidae Steph. and Pirl. 



6. Endopodites of all uropods fused with basipodites 



VII. Family Scinidae Stebb. 



— Rami of uropods free 7. 



7. Pereon in sexually mature females spherically bulging, males with 

 scinoid body. Antennae I attached to middle part of anterior surface 

 of head V. Family Mimonectidae Bov. 



— Pereon in sexually mature females not spherically bulging; both sexes 

 with identical scinoid body. Antannae I attached to dorsal part of 

 anterior surface of head VI. Family Proscinidae Pirl. 



8. Antennae I attached to lower surface of head; 1st article of flagellum 

 in males enlarged and curved like a boomerang. Antennae II zigzag 

 in males. Superfamily Platysceloidea 16. 



— Antennae I attached to anterior surface of head; 1st article of flagel- 

 lum in males differs in structure. Antennae II not zigzag in males. . . 

 9. 



9. Antennae I attached in special socket on anterior surface of head; 

 1st article in males triangular, distal segments articulated subtermi- 

 nally. Gills only on pereon somites V and VI. Superfamily Lycaeop- 

 soidea XV. Family Lycaeopsidae Chevr. 



— Special socket for attachment of antennae I absent. Distal segments 

 of antennae I in males articulated to proximal segment, terminally, 

 or absent. Gills usually on pereon somites II-VI, rarely on somites 

 IV-VI 10. 



10. Flagellum of antennae I in both males and females with large 1st and 

 few (often rudimentary) subsequent articles. Antennae II comprise 

 several cylindrical articles and even in males without long whiplike 

 flagellum, sometimes rudimentary. Superfamily Vibilioidea 11. 



