MARINE GAMMARIDEAN AMPHIPODA 367 



Tryphosoides Schellenberg 



Tryphosoides Schellenberg, 1931. 



Type-species: T. falcata Schellenberg, 1931 (monotypy). 



Epistome not produced (apparently not as in "Tryphosa") ; mandib- 

 ular molar ridged, palp attached level uith molar; gnathopod 1 

 subchelate, article 6 longer than 5 ; coxa 1 scarcely narrowed, slightly 

 beveled anteroventrally; outer ramus of uropod 3 uniarticulate {"Try- 

 phosa") ; accessory flagellum vestigial, 2-articulate; telson of medium 

 length, deeply cleft. Species: 1, antiboreal S. America, littoral. 

 Possibly synonymous mth Uristes. See Rijcus. 



Uristes Dana 



Uristes Dana, 1849.— Stebbing, 1906. 

 ?Pseudotryphosa Sars, 1895. 

 Uristoides Schellenberg, 1931. 



Type-species: U. gigas Dana, 1852a; 1853 (monotypy of Dana, 

 1852a). See Stebbing, 1888 (as Tryphosa antennipotens) . 



Head small, mouthparts largely covered by coxae 1-2 {Tmetonyx and 

 Tryphosella) ; epistome and upper Up generally small and incon- 

 spicuous, ojten slightly produced differentially {Tmetonyx and Try- 

 phosella); mandibular molar setulose, palp attached level with molar; 

 gnathopod 1 subchelate or nearly simple, article 6 longer than 5 

 {Tmetonyx usually) ; coxa 1 narrowing slightly distally {Hippomedon) ; 

 telson of medium length, deeply cleft. Species: 23, cosmopolitan, 

 coldwater submergent, littoral to abyssal. 



Valettia Stebbing 



Valettia Stebbing, 1888; 1906. 



Type-species: V. coheres Stebbing, 1888 (monotypy). 



Apparently epistome and upper hp not prominent; mandibular 

 molar ridged, primary cutting edge of mandible toothed, palp attached 

 level with molar; setae of inner plate of maxilla 1 mostly terminal 

 {Valettiopsis) ; outer plates of maxilhped acutely produced apically; 

 coxa 2 short, broad, subrounded, scarcely concealing coxa 1, latter not 

 shorter than coxa 2 and of similar shape {Valettiopsis) ; gnathopod 

 1 weakly chelate, palm transverse; gnathopod 2 rather stout, article 5 

 shorter than 6; inner ramus of uropod 2 slightly constricted; telson 

 short, deeply cleft. Species: 1, antarctic, abyssal. 



