MARINE GAMMARIDEuAN AMPHIPODA 187 



7. Uropod 2 with one ramus (fig. 800 8 



Uropod 2 with two rami (fig. 80^) 10 



8. Pleopod 3 with one ramus, [article 3 of antenna 1 longer than article 1]. 



Runanga 



Pleopod 3 with two rami, [article 3 of antenna 1 rarely longer than article 



1] 9 



9. Male gnathopod 2, not gnathopod 1, complexly subchelate (fig. 790, head 



with thorn-like rostrum and eyes Cerapus 



Male gnathopod 1, not gnathopod 2, complexly subchelate, head with ob- 

 solescent rostrum and no eyes Chevreuxius 



10. Inner rami of uropods 1-2 less than half as long as outer rami (fig. 80j) . 



Pseudericthonius 

 Inner rami of uropods 1-2 usually subequal to outer rami 11 



11. Antenna 1 lacking accessory flagellum 12 



Antenna 1 bearing accessory flagellum 15 



12. Male gnathopod 2 complexly subchelate (carpochelate) (fig. 79A:) . Ericthonius 

 Male gnathopod 2 not complexly subchelate 13 



13. Pleonites 4-5 coalesced Kamaka 



Pleonites 4-5 separate 14 



14. Male gnathopod 2 chelate (propodochelate) Cerapopsis 



Male gnathopod 2 subchelate (fig. 79j) Gaviota 



15. Accessory flagellum multiarticulate 16 



Accessory flagellum 1-articulate 19 



16. Coxae angular 17 



Coxae with softly rounded corners 18 



17. Article 6 of gnathopod 2 an elongate rectangle, parachelate or palm trans- 



verse, antennae usually much shorter than body and flagellum of antenna 

 2 scarcely longer than peduncular article 5, peduncle of uropod 3 often 

 expanded medially very strongly, antenna 2 generally considered stout, 



often strongly so Unciola 



Article 6 of gnathopod 2 ovate or trapezoidal, expanded, palm oblique, 

 antennae usually as long as or longer than body, flagellum of antenna 2 

 nearly as long as all articles of peduncle, peduncle of uropod 3 rarely 

 expanded medially and usually poorly so, antenna 2 very slender. 



Neohela 



18. Inner plate of maxilla 1 with one seta, ramus of uropod 3 about 1.5 times 



as long as peduncle Unciolella 



Inner plate of maxilla 1 with about 10 setae lining medial edge, ramus of 

 uropod 3 about twice as long as peduncle Parunciola 



19. Male gnathopod 1 complexly subchelate Grandidierella 



Male gnathopod 1 simply subchelate 20 



20. Male antenna 2: articles 3-5 stout (fig. 766), [often cuspidate], uropod 3 



with asymmetrically prolonged peduncle (fig. 80z), or uropod 2 with 



vestigial inner ramus Unciola 



Male antenna 2: articles 3-5 slender (figs. 76a,d, 77a), uropod 3 with sym- 

 metrical peduncle (fig. 80/), rami of uropod 2 subequal. 



Unciolella (juvenile) 



21. Mandibular palp 1-articulate (fig. 78e) Siphonoecetes 



Mandibular palp 2-articulate (fig. 78/) Corophium 



285-135 O - 69 - 13 



