MARINfiE GAMMARIDEAN AMPHIPODA 435 



Sebidae 



Figure 159 



Diagnosis. — Accessory flagellum 2-articulate, elongate; molar of 

 mandible obsolescent; plates of maxillipeds of medium size; gnatho- 

 pods 1 and 2 chelate, gnathopod 1 larger than 2, article 3 of gnatho- 

 pod 2 elongate; antenna 1 peduncle elongate; uropod 3 uniramous; 

 telson entire; urosomites 2-3 coalesced. Monogeneric. See Lysi- 

 anassidae, Leucothoidae, Anamixidae, Pagetinidae. 



Description. — Accessory flagellum 2-articulate, elongate; body 

 smooth or with poorly developed carinae, urosomites 2-3 coalesced; 

 mandibular palp article 3 short, molar evanescent; remaining mouth- 

 parts basic although plates of maxilUpeds somewhat small; coxae of 

 medium length, rounded-quadrate below; gnathopods chelate, rather 



Figure 159. — Sebidae: Seha armata Chevreux (1900): a, lateral view; b, upper lip; c, 

 mandible; d, maxilla 1; e, maxil-liped;/,^, gnathopods 1,2; h, telson; i, antenna l;j, uropod 

 3. Seba saundersi Stebbing (1888): k, lower lip. 



