308 U.S. NATIONAL MUSEUM BULLETIN 271 



14. Gnathopods simple Alicella 



Gnathopods subchelate Paralicella 



15. Gnathopod 1 simple 16 



Gnathopod 1 subchelate 17 



16. Rami of iiropod 3 subequal to each other in length Ichnopus ^ 



Inner ramus of uropod 3 vestigial, scale-like Clepidecrella 



17. Head globular, maxilla 1 with sickle-shaped setae on inner lobe (fig. 127d). 



Hirondellea 

 Head other than globular, maxilla 1 with normal setae on inner lobe . . 18 



18. Maxillipedal palp article 4 reduced in size (fig. 128o) .... Centromedon 

 Maxillipedal palp article 4 of normal size 19 



19. Coxa 1 normally quadrate, untapering, cephalon lacking lateral lobes or 



strongly truncate anteriorly (fig. 1216), coxa 5 as long as coxa 4. 



Lepidepecreoides 

 Coxa 1 normally quadrate, untapering, cephalon with lateral lobes, coxa 5 



much shorter than coxa 4 proceed to 24 



Coxa 1 tapering distally, slightly shortened, cephalon with lateral lobes, 



coxa 5 much shorter than coxa 4 . . Lepidepecreopsis and Tryphosella 



20. Coxa 1 very slightly triangular, tapering distally (figs. 129c,k) .... 21 

 Coxa 1 quadrate, or rounded, expanded or unexpanded distally (figs. 129 



a,b,h) 24 



21. Outer ramus of uropod 3 uniarticulate Tryphosoides 



Outer ramus of uropod 3 biarticulate 22 



22. Head small, epistome and upper lip inconspicuous. 



Uristes ^ [ = Uristoides] ?some species of Cheirimedon 

 Head large, epistome and upper lip prominent from lateral view ... 23 



23. Dactyl of gnathopod 1 with inner accessory tooth. 



some species of "Tmetonyx" auct. [ = Tryphosella] 

 Dactyl of gnathopod 1 lacking accessory tooth. 



Tryphosella ^ [ = "Tryphosa" auct.] 



24. Telson not longer than broad, always cleft less than halfway. 



Rifcus and Boeckosimus [ = "Onisim,us" auct.] 

 Telson longer than broad (or if short, then cleft halfway or more) ... 25 



25. Gnathopod 1 "simple" 26 



Gnathopod 1 subchelate 28 



26. Gnathopod 1 perfectly simple, maxillipedal dactyl stunted . Menigratopsis 

 Gnathopod 1 very slightly subchelate, palm small, maxillipedal dactyl 



elongate 27 



27. Uropod 2 with simple inner ramus Paroneslmus (in part) 



Uropod 2 with incised inner ramus . . "Anonyx" cicadoides Stebbing, 1888 



28. Mandibular molar densely covered with setules 29 



Mandibular molar ridged or weakly punctate, setules generally absent or 



inconspicuous 30 



29. Coxa 1 expanded distally, unguiform dactyl of gnathopod 1 usually lacking 



accessory tooth, upper lip slightly or strongly protruding in front of 

 epistome, inner ramus of uropod 2 often incised, palp article 4 of maxilliped 

 unguiform Anonyx 



- Menigrates angustipes Gurjanova (1962) may key to this position inadvertently but note diagnosis of 

 Ichnopus does not otherwise fit Meniirates. 

 ■" f^ee also "Orchomene" takoradia J. L. Barnard (1961); "Uristes" velia J. L. Barnard (1961). 



