302 U.S. NATIONAL MUSEUM BULLETIN 271 



11. Uropod 3 : inner ramus vestigial or absent 12 



Uropod 3: inner ramus more than half as long as outer ramus 13 



12. Uropod 3: inner ramus vestigial, article 1 of antenna 1 flagellum 5 times as 



long as next article Oneslmoides ^ 



Uropod 3: inner ramus absent or represented by a spine, article 1 of antenna 1 



flagellum not longer than next article Paronesimoides 



Uropod 3: inner ramus vestigial, article 1 of antenna 1 flagellum not longer 



than next article Clepidecrella ^ 



13. Gnathopod 1 simple 14 



Gnathopod 1 distinctly, though often minutely subchelate 17 



14. Mandibular palp attached level with molar (fig. 126to), coxa 4 scarcely 



excavate posteriorly (fig. 117a) Paralibrotus and Menigrates 



Mandibular palp attached well proximal of molar (fig. 126/i), coxa 4 excavate 

 posteriorly (fig. 1196) 15 



15. Palp article 4 of maxilliped tiny (fig. 128A;) Nannonyx 



Palp article 4 of maxilliped well developed (fig. 128c) 16 



16. Epistome and upper lip together strongly produced and separated by a 



slit Aruga (in part) [^^Lysianassa] 



(and possibly [Pronannonyx] and see Adeliella) 



Epistome and upper lip together not strongly produced, and apparently 



coalesced Parambasia 



17. Maxillipedal palp 3-articulate 18 



Maxillipedal palp 4-articvdate 19 



18. Maxilliped: inner plates obsolescent (fig. 128j) Perrierella 



Maxilliped: inner plates as long as palp (fig. 128g') Normanion 



19. Gnathopod 1 : palm excavate (mouthparts unknown) . . . Pseudambasia 

 Gnathopod 1: palm not excavate 20 



20. Mandibular palp attached level with molar (fig. 126m) 21 



Mandibular palp attached proximal to molar (fig. 126/i) or molar absent . 23 



21. Maxilla 2 strongly setose (fig. 127p), coxa 1 visible 22 



Maxilla 2 poorly setose (fig. 121 k), coxa 1 nearly concealed by coxa 2. 



Adeliella 



22. Mandibular molar small, conical, attenuated, setulose, gnathopod 1 article 6 



enlarged Koroga 



Mandibular molar of medium size, triturative, gnathopod 1 not enlarged. 

 "Pseudalibrotus" (^Onisimus) and "Onisimus" [=Boeckosimus (in part)] 



23. Rami of uropod 3 reduced in size, inner ramus about half as long as peduncle 



(fig. 132k) Nannonyx 



Rami of uropod 3 as long as or longer than peduncle (fig. 1325r) .... 24 



24. Article 6 of gnathopod 1 very stout, enlarged (fig. 1290 25 



Article 6 of gnathopod 1 small, rectangular (fig. 129d). 



some species of Orchomene and [Allogaussia] 



25. Mandibular molar of medium size, triturative, article 4 of maxillipedal palp 



short Pseudokoroga 



Mandibular molar small, conical, attenuated, setulose, article 4 of maxilli- 

 pedal palp long Koroga 



- See also Adeliella. 



3 Sec also Parawaldeckia kidderi (Smith) (p. 357), distinguished from Clepidecrella by extreme proximal 

 location of mandibular palp. 



