2 8 DISCOVERY REPORTS 



SYSTEMATIC ACCOUNT 

 GAMMARIDEA 



Family LYSIANASSIDAE 



Stebbing, 1906, pp. 8 and 717-721. 

 Schellenberg, 1926, p. 239. 

 Barnard, 1930, p. 318. 



Remarks. In dealing with several genera in this family the characters of the epistome 

 plus upper lip, and the profile outline of pleon segment 4 have been regarded as of 

 specific importance. Some other authors have assumed an extensive variability in these 

 characters, without adducing definite proof of such variability in every case, and on this 

 basis have attempted to lump many forms together under one name, whereby the 

 "species" has acquired a "wide distribution". An outstanding example of this pro- 

 cedure is the sinking of the Australian Tryphosa camelus, Stebb. as a synonym of the 

 Norwegian T. sarsi (cf. Chilton, 1921a, p. 43). 



On the contrary I have found in examining the present collection very little evidence 

 of variability. Enlarged drawings of the profiles of pleon segment 4 of several indi- 

 viduals, if superimposed, would naturally not coincide exactly; but the essential and 

 characteristic curve of the profile is maintained. It is thus a good specific character. 



One feature has not been taken into account in dealing with the more closely allied 

 representatives of this family, viz. the surface sculpturing. The possible importance of 

 this was not fully realized until the bulk of this report was completed and the Ponto- 

 geneiids were being studied (infra, p. 195). I may suggest, however, that the value of 

 this character be investigated in, e.g., the genera Orchomene, Orchomenella and Try- 

 phosa. The Cape form of chilensis (plicata) has the surface nitidulous with scattered pits, 

 whereas rossi has a perfectly nitidulous surface without any pits. 



Stebbing, 1906, p. 11. 

 Schellenberg, 1926, p. 239. 

 Barnard, 1930, p. 318. 



Genus Kerguelenia, Stebb. 



Kerguelenia palpalis, n.sp. 



Schellenberg, 1926, p. 241, fig. 2. (Kerguelenia sp., juv.) 

 Occurrence: St. 175. South Shetlands. 1 (? $) 6 mm. 1 



Remarks. This specimen seems to belong to the same species as the young specimen 

 mentioned by Schellenberg. It has the same stout palp on the maxilliped as figured by 

 him, the biramous 3rd uropod, and the distally expanded and lobed 2nd joint of 

 peraeopod 3. First antenna with 6-jointed flagellum, 4-jointed accessory flagellum. 

 Second antenna with 6-jointed flagellum. Eyes as in boreal is. 



1 Except where otherwise stated, all measurements are taken from the point of the head or rostrum to 

 the end of the telson. 



