MARINE GAMMARIDEAN AMPHIPODA 383 



Halicreion Boeck 



Halicreion Boeck, 1871. — Stebbing, 1906. 



Type-species: Oediceros aequicornis Norman, 1869a (monotypy 

 and subsequent synonymy). See Sars, 1895 (as H. longicaudatus) . 



Cutting edge of mandible projecting slightly, poorly but distinctly 

 toothed, molar large, ridged; inner lobes of lower lip separate; gnatho- 

 pods similar to each other, subchelate, stout, article 5 strongly lobate, 

 lobe on gnathopod 2 sufficiently long to appear to be guarding article 

 6; uropod 3 very long, uropod 2 not exceeding peduncle of uropod 3; 

 eyes contiguous (Exoediceros) . Species: 3, bipolar, coldwater littoral 

 to bathyal (730 m, S. Atlantic). 



Methalimedon Schellenberg 



Methalimedon Schellenberg, 1931. 



Type-species: M. nordenskjoldi Schellenberg, 1931 (monotypy). 



Cutting edge of mandible projecting, toothed, molar large, ridged; 

 inner lobes of lower lip separate; gnathopods similar to each other, 

 feeble, subchelate, article 5 not lobate; uropod 2 apparently reaching 

 end of uropod 3 ; eyes unpaired, coalesced, base of pereopod 5 broadly 

 lobed distally (Parhalimedon) . Species: 1, subantarctic, littoral (to 

 310 m). 



Monoculodes Stimpson 



Monoculodes Stimpson, 1853. — Stebbing, 1906. 

 Kroyera Bate, 1857a, 1858a. 



Type-species: M. demissus Stimpson, 1853 (monotypy). Species 

 obscure. 



Antenna 1 not longer than antenna 2, article 3 less than half as long 

 as article 1 (Monoculopsis) ; antenna 2 neither enlarged nor elongate 

 {Oediceroides) ; cutting edge of mandible projecting, toothed, molar 

 large, ridged; gnathopods dissimilar, subchelate, gnathopod 1 usually 

 stout, lobe of article 5 long or short, but usually not appearing to 

 guard article 6; gnathopod 2 usually slender, lobe of article 5 usually 

 very long and guarding article 6; both gnathopods merging to those of 

 Oediceroides; uropod 2 reaching end of uropod 3. Species: 46, cosmo- 

 politan in N. Hemisphere, littoral to bathyal (only 2 species in S. Hem- 

 isphere, Tasman Sea, 610 m, and S. Georgia area). 



Monoculopsis Sars 



Monoculopsis Sars, 1895.— Stebbing, 1906. 



Type-species: Monoculodes longicornis Boeck, 1871 (monotypy). 



