MARESTE GAMMARIDEAN AMPHIPODA 307 



15. Article 7 of gnathopod 1 with accessory tooth. 



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

 Article 7 of gnathopod 1 simple .... Tryphoselia [^"Tryphosa" auct.] 



KEY M 



1. Palp of mandible attached proximal to molar (fig. 126z) 2 



Palp of mandible attached level with molar or molar absent (figs. 12Qj,k) . 11 



2. Article 1 of antenna 1 strongly produced distally and dorsally crested 



(fig. 124d) Lepidepecreum 



Article 1 of antenna 1 weakly or not produced distally, not dorsally crested 

 (fig. 124:h) 3 



3. Gnathopod 1 simple and small 4 



Gnathopod 1 subchelate (or very large and seemingly simple) 7 



4. Outer ramus of uropod 3 uniarticulate Socarnopsis 



Outer ramus of uropod 3 biarticulate 5 



5. Inner ramus of uropod 2 constricted Socarnoides 



Inner ramus of uropod 2 simple 6 



6. Telson cleft one third of its length, prebuccal parts not prominent (fig. 125d), 



articles 2-3 of antenna 1 peduncle half as long as article 1 of primary 



flagellum Menigrates 



Telson cleft halfway or more, prebuccal parts prominent (fig. 125c), articles 

 2-3 of antenna 1 as long as article 1 of primary flagellum. 



Waldeckia and Socarnes (see Key P, couplet 21) 



7. Article 3 of gnathopod 1 elongate and slender as in typical lysianassid 



gnathopod 2, articles 5-6 also elongate and slender (fig. 129z). 



Pseudorchomene 

 Articles 3,5,6 of gnathopod 1 stout, not relatively elongate (fig. 129d) . . 8 



8. Article 4 of antenna 2 very tumid, article 5 slender Lysianella 



Article 5 of [male] antenna 2 very tumid, stouter and longer than article 4. 



Microlysias ' 

 Neither of articles 4-5 of antenna 2 expanded 9 



9. Articles 5 and 6 of gnathopod 1 not immensely enlarged (fig.l29d) (also 



check Lepidepecreum). 



Orchomene [ = Orchomenella] and juveniles of Pseudokoroga 

 Articles 5 and 6 of gnathopod 1 immensely enlarged (fig. 1290 .... 10 



10. Maxillae slender (fig. 1270, maxillipedal palp article 4 short, mandibular 



molar triturative Pseudokoroga 



Maxillae stout (fig. 127o), maxillipedal palp article 4 elongate, mandibular 

 molar nontriturative Koroga 



11. Mandibular molar laminate, conical, not cuboidal, surface simple, lacking 



ridges, often weakly setulose, or molar absent 12 



Mandibular molar cuboidal or columnar, surface usually bearing conspicuous 

 ridges and spines, or distinct punctations, or densely setulose if not fully 

 cuboidal and slightly attenuate (figs. 126e,g,j,m) 20 



12. Gnathopod 1: article 6 very large and expanded, more than 3 times as long 



as article 5 (fig. 1290 Koroga and Cheirimedon 



Gnathopod 1: article 6 small, never more than 1.5 times as long as article 5. 13 



13. Inner lobe of maxilla 1 bearing five or more setae 14 



Inner lobe of maxilla 1 bearing two or fewer setae 15 



Possibly article 5 of Microlysias has been misidentifled. 



