MAEESTE GAMMARIDEAN AMPHIPODA 297 



14. Mandibular palp attached level with molar or at its proximal corner . . 15 

 Mandibular palp attached strongly proximal to molar. 



(exceptional) Orchomene 



15. Coxa 1 tapering slightly and partially covered by coxa 2, inner ramus of 



uropod 2 simple Tryphosella 



Coxa 1 fully expanded distally and freely visible, inner ramus of uropod 2 

 deeply constricted Tryphosites 



16. Telson cleft less than one fourth of its length (figs. 128n,o,p) . . . Key J 

 Telson cleft one third or more of its length (figs. I28s,t,v) 17 



17. Coxa 2 concealing anteroventral corner of coxa 1; or otherwise shielding 



coxa 1; or coxa 1 reduced in size or subtriangular (figs. 1196, 122c?, 1236). 



KeyL 

 Coxae 1 and 2 both large and visible and not triangular (figs. 117a, 118a) . 18 



18. Mandible lacking palp Stephensenia 



Mandible bearing palp Key M 



19. (from couplet 11.) Coxa 1 slightly or strongly reduced in size or tapering 



distally (figs. 1196, 122d, 1236), often partially covered by coxa 2 . Key O 



Coxa 1 of normal size, anterior and posterior edges parallel or coxa 1 distally 



expanded 20 



20. Mandible lacking palp Stephensenia 



Mandible bearing palp Key M 



21. (from couplet 7.) Mandible lacking palp Stephensenia 



Mandible bearing palp 22 



22. Article 7 of gnathopod 1 minute, shrouded among setae or cirri attached to 



articles 7 or 6 Key K 



Article 7 small or large, visible, usually claw-like 23 



23. Pereopod 1 prehensile and resembling a large gnathopod. 



Endevoura and Ensayara 

 Pereopod 1 simple 24 



24. Mandibular palp attached distinctly proximal to molar or if molar absent 



palp distinctly proximal in position Key P 



Mandibular palp attached level with or distal to molar, or if molar absent 

 palp attached distinctly toward distal end of mandible Key Q 



KEY A 



These are highly aberrant genera, not certainly placed in the Lysianas- 

 sidae. Shoemaker (1945a) believed Thoriella to be in the family 

 Talitridae but the second gnathopod is distinctly that of a lysianassid. 

 Chevreuxiella and Danaella bear resemblance to cyphocarids (key F) 

 by reason of their coxae. 



1. Maxillipedal palp absent (fig. 128Z) ; pereonites 3-6 hugely inflated, forming a 



globular body (fig. 121a) Danaella 



Maxillipedal palp present even if degraded; pereonites 3-6 not larger than 

 other body segments (fig. 1176) 2 



2. Urosomc composed of two segments (fig. 124a) Chevreuxiella 



Urosome composed of three segments (fig. 122a) Thoriella 



KEY B 1 



1. Eyes and gnathopod 1 together powerfully developed (fig. 123a) 2 



Eyes and gnathopod 1 not together powerfully developed 3 



