244 U.S. NATIONAL MUSEUM BULLETIN 271 



Accessory flagelliim 4- or more articulate; lower lip with inner lobes; 

 inner plates of maxillae setose only terminally; gnathopods normal; 

 uropod 3 exceeding nropod 1, rami equal, outer 1-articulate; telson 

 cleft shortly; metasome and urosome dorsally toothed, urosome with 

 scattered spines; maxillipedal palp with only three articles. Species: 

 1, temperate N. E. Atlantic, littoral. 



Maeropsis Chevreux 



Maeropsis Chevreux 1919; 1927. 



Type-species: M. perrieri Chevreux, 1919, 1927 (monotypy). 



Accessory flagellum more than 4-articulate; lower lij) with inner 

 lobes; inner plate of maxilla 1 setose only terminally, of maxilla 2 

 densely setose medially; gnathopods normal; uropod 3 not exceeding 

 uropod 1, rami equal, rectangular, outer 1-articulate; telson deeply 

 cleft; body lacking dorsal teeth or spines. Species: 1, N. Atlantic, 

 bathyal (698 m). 



"Marine Carinate Gammarus^^ 



Species: Qammarus mucronatus Say, 1818. 



Accessory flagellum 3- or more articulate; lower lip with inner lobes; 

 inner plates of maxillae 1-2 densely setose medially; gnathopods 

 normal, subequal in size; uropod 3 exceeding uropod 1, rami long, 

 outer 2-articulate, inner slightly shorter than outer; telson deeply 

 cleft; each metasomite with one dorsal tooth; urosomites with dorsal 

 bundles of spines. Species: 1, Atlantic and Gulf United States, 

 littoral lagoonal. Formerly included with Baikalian Carina gammar us 

 but having affinities with freshwater Rivulogammarus. See Meso- 

 gammarus. 



Megaliiropus Hoek 



Megalonoura Herdman, 1889 (nonien nudum). 



Megaliiropus Hoek, 1889.— Stebbing, 1906.— K. H. Barnard, 1940. 



Phylluropus K. H. Barnard, 1932. 



Type-species: M. agilis Hoek, 1889 (monotypy). See Chevreux 

 and Fage, 1925. 



Accessory flagellum 2-articulate; lower lip with inner lobes; inner 

 plates of maxillae 1-2 densely setose medially; gnathopods feeble, 

 poorly subchelate; uropod 3 exceeding uropod 1 or not, rami equal, 

 foliaceous, outer 1-articulate; telson deeply cleft; metasome and 

 urosome often dorsally serrate. Species: 3, bi-boreal, littoral (pri- 

 marily neritic). 



