6 R. NORRIS WOLFENDEN. 



N. Polar. S. Polar. 



Gaidius tenuispinus') G. tenuispinus 



Irevispinm] re P Iaced b ? major 



antarcticus 

 Microcalamts pusillus (= Pseudo- M.pusillus 



/a In /ii's pygmwus) 



Heterorrhaldus norwtgkus replaced by H. austrinus 



compactus longicornis 



Emlmta norwegica replaced by E. antarctka 



glacialis ., austrina 



larbata similis 



Haloptilm spinifrms replaced by H. ocellatus 



spiniceps 



S]rinocalanus longicornis replaced by S. antarcticus 



Undeuclueta spectabilis replaced by U. major 



Oitkona similis replaced by 0. similis 



helgolandica curvata 



conifera conifera 



notopus notopus 



friffida 



In the North Polar Sea, as Prof. Sars remarks, besides the few distinctly Arctic 

 species are many which extend southwards to the warmer seas, and the North Polar 

 basin copepod fauna has a pronounced resemblance to that of the North Atlantic 

 basin, the greater number of species being common to both, and some deep-water forms 

 of the Norwegian Sea are often surface forms in the North Polar basin. A few forms 

 regarded as quite southern also occur in the North Polar Sea. 



So far as the distribution can be followed from the ' Gauss ' collections, it may be 

 said that, of the typical Antarctic fauna its representatives diminish gradually to latitude 

 40 S. (i.e. about the latitude of St. Paul and New Amsterdam) north of which they do 

 not appear, but extend westwards to those stations situated directly south and westward 

 to 10 E. as a limit of the Cape of Good Hope, north of which no typically Antarctic 

 species appears. 



North of Kerguelen, i.e. 50 S. lat., no Antarctic species appear to extend, while the 

 typically subtropical species of the Indian Ocean extend as far south as latitude 30 S., 

 where their southern extension appears to be arrested. There is thus a barrier between 

 lat. 40 and 50 S. and between long. 10 and 80 E. as indicated by the ' Gauss ' 

 collections, at which extension northwards of Antarctic species and southwards of Indian 

 Ocean subtropical species is prevented, or at any rate, does not occur. While the same 

 collections indicate that the Antarctic species extend northwards into the Atlantic Ocean 

 in gradually diminishing numbers, only as far as lat. 40 S., north of which they do not 

 occur, a few typically Atlantic deep-water species find their way into the Antarctic Sea 

 (such are Heterorrhdbdus profundus, Labidocera acutifrons, Metridia princeps, Lucicutia 

 grandis, Gaidius major, Arietellus setosus). 



Until the ' Gauss ' collections are fully examined it is of course rash to say that no 



