MARINE GAMMARIDEAN AMPHIPODA 305 



KEY J 



Both Koroga and Orchomene {^fAllogaussia) are repeated here, in 

 the event their quantitatively expressed characters were overlooked 

 in previous keys. 



1. Coxa 1 nearly concealed by coxa 2 Adeliella 



Coxa 1 fully visible 2 



2. Mandibular palp attached level with molar (fig. 126m) 3 



Mandibular palp attached proximal to molar (fig. 126i) 5 



3. Gnathopod 1 subchelate, inner ramus of uropod 3 as long as article 1 of outer. 



4 

 Gnathopod 1 simple, inner ramus of uropod 3 vestigial .... Clepidecrella 



4. Mandibular molar triturative "Onisimus" [ = Boeckosimus] 



Mandibular molar simple Menigrates 



5. Gnathopod 1 : article 6 not wider than article 3 6 



Gnathopod 1: article 6 distally twice as wide as article 3 (fig. 1290. 



Koroga and Pseudokoroga (see Key G for distinction) 



6. Gnathopod 1 subchelate Orchomene [ = 'fAllogaiissia] 



Gnathopod 1 simple Socarnella and Menigrates 



KEY K 



Gnathopod 1 is slender, the dactyl hidden in a tuft of setae or cirri 

 (fig. 130m). Ichnopus bears resemblance to this group as a genus with 

 a posterior or distal brush of setae on the dactyl. Pseudoanonyx is only 

 marginally assignable to this group. 



1 . Gnathopod 1 stout and minutely and transversely subchelate or chelate, palp 



article 4 of maxilliped stout and subclavate Pseudoanonyx 



Gnathopod 1 slender and simple, or palm very oblique, palp article 4 of 

 maxilliped slender and claw-like 2 



2. Mandible lacking molar, article 6 of pereopods 1-2 slightly longer than 



articles 4 and 5 combined (fig. 131c) and slightly prehensile. 



Scopelocheiropsis 



Mandible bearing molar, article 6 of pereopods 1-2 shorter than or equal to 



articles 4 and 5 combined (fig. 117a) 3 



3. Lower lip with major lobes fully excavate medially, forming a medial gap 



(fig. 125s) Bathycallisoma 



Lower lip with medial edges of major lobes closely appressed (fig. 125r) . . 4 



4. Gnathopod 2 minutely chelate (fig. 131/) 5 



Gnathopod 2 subchelate (fig. 131j) 6 



5. Epistome flat in front (fig. 125o) Aroui 



Epistome grossly lobate in front (fig. 125m) Scopelocheirus 



6. Inner plate of maxilla 1 setose only terminally and subterminally, dactyl of 



gnathopod 1 not distinct from cirri (fig. 129m) .... Paracallisomopsis 



Inner plate of maxilla 1 setose medially, dactyl of gnathopod 1 distinct from 



cirri (fig. 130m) (see other characters under Paracallisomopsis diagnosis) . 7 



7. Article 2 of gnathopod 1 linear, not glandular (fig. 130m), coxa 5 much larger 



than and partially covering coxa 6 Paracallisoma 



Article 2 of gnathopod 1 swollen, glandular (fig. I29g), coxa 5 not much larger 

 than and not covering coxa 6 Eucallisoma 



