MARINE GAMMARIDEAN AMPHIPODA 463 



elongate and deeply cleft. Species: 9, cosmopolitan, cold-water, 

 deep littoral to abyssal. 



Tiron Liljeborg 



Tiron Liljeborg, 1865.— Stebbing, 1906.— Shoemaker, 1955. 

 Tessarops Norman, 1868 (homonym, Arachnida). 



Type-species: Lysianassa spinifera Stimpson, 1853 (monotypy 

 and subsequent synonomy). See Sars 1895 (as T. acanthurus). 



Mandible of medium size, molar of medium size, strongly projecting, 

 columnar and triturative; coxa 3 softly rectangular, posterior margin 

 almost parallel with anterior margin and not strongly excavate; coxa 

 4 variable, typically adze-shaped and almost as long as coxa 3, surface 

 area of coxa 4 nearly equal to coxa 3 ; rarely coxa 4 distinctly shorter 

 and smaller than 3 and weakly comma-shaped ; article 6 of gnathopods 

 a nearly perfectly linear rectangle, simple and lacking distinct locking 

 spine(s); telson elongate and deeply cleft. Species: 8, cosmopolitan, 

 littoral (rarely to bathyal). 



Superfamily Talitroidea 



[includes Talitridae, Hyalidae, and Hyalellidae] 

 Figures 168, 169 



Diagnosis. — Accessory flagellum absent; mandible lacking palp; 

 uropod 3 essentially uniramous; tiny scale-like inner ramus rarely 

 present. See Phliantidae, Dogielinotidae, Eophliantidae. 



Description. — Accessory flagellum absent; body rarely with teeth 

 or carinations; coxae of medium size; mandible lacking palp, molar 

 large and strongly triturative (except Najna) ; lower lip without inner 

 lobes; palp of maxilla 1 often reduced or absent; maxilliped occasion- 

 ally with fewer than four palp articles; gnathopods usually powerful, 

 occasionally simple or feeble; uropod 3 small, usually with one ramus, 

 inner ramus reduced to a scale when present; telson very short, entire, 

 apically emarginate, cleft, or appearing completely bilobate. 



Relationship. — The following families, lacking mandibular palps, 

 differ from the Talitroidea in their coalesced fifth and sixth pleonites : 

 Dexaminidae, Prophliantidae, and Kuriidae. 



The Dogielinotidae, which probably should be assigned to the 

 Talitroidea, differ by their haustoriid-phoxocephalid aspect, with 

 multispinose antennae, short spinose pereopods and shape of head, 

 bearing a conspicuous but small rostrum. Their epistome has a nasi- 

 form anterior lobe. 



The Eophliantidae differ from talitroids by their cylindrical bodies. 



