604 К- Stephensen. 



3F. Boreoarctic littoral forms, which range from America 



eastwards to and including Siberia, so that they are 



probably circumpolar, and which in Europe are found 



S. of Finmarken. (Some also live in deep water.) 



Sabinea septemcarinata. Atylus carinatus. 



Spirontocaris polaris. ? Pontogeneia inermis. 



Onisimus Edwardsii. Halirages fulvocinctus. 



— plautus. Gammarus locusta. 



Orchomene minutus. Ampelisca Eschrichtii. 



? — serratus. Haploops tubicola. 



Pontoporeia femorata. Byblis Gaimardii. 



Monoculodes borealis. Podocerus (Ischyrocerus) anguipes. 



Pleustes panoplus. Diastylis Rathkei. 



— scorpioides. 



Sabinea septemcarinata in contrast to S. Sarsii is essentially arctic. 

 W. of Greenland it is found from Ivigtut (ca. 61° N.) to 81°44' N. 

 (Grinnell Land) and Gaasefjord (arctic America, Sars 2nd "Fram" 

 Exped.), most often from 72° N. to 79^/3° N. At E. Greenland it is 

 most common between 70°27' N. and 74°33' N. ; the Danmark Exped. 

 has taken it 5 times. It is also known from eastern N. America N. 

 of 42^3° N., Jan Mayen, Iceland, Norway N. of Lofoten, Spitzbergen 

 and perhaps Shetland. Eastward it enters the White Sea and the 

 Kara Sea and has been taken N. of Siberia, but not in the Bering 

 Strait or N. America. Sars (Crust, in Nansen, '.'Norweg. North-Polar 

 Exped.", voll, 1900) mentions the myto-stage from 78° N., 136E. (N. 

 of New Siberia). It occurs on the whole in very shallow water, 

 usually in but a few (5 — 10—25) fm. 



Spirontocaris polaris is found at arctic America (Sars 2nd 

 "Fram" Exped.), W. and E. Greenland, Barents Sea, Kara Sea and 

 Siberia; the southern boundary is eastern N. America N. of 41°34V2' N., 

 Shetland, Hebrides and Skager Rak. It is also found N. and S. of 

 Siberia. Birula writes (1910, p. 18) regarding its circumpolarity : 

 "Im Karischem Meere ist Hetairus polaris schon von der Dijmphna- 

 Expedition erbeutet worden; im ostsibirischen Teile des Eismeeres 

 wurde diese Art bisher noch nicht erwähnt; daher erweitert die 

 Auffindung desselben im Nordenskiöld-Meere und am Meridiane der 

 Neusibirischen Inseln durch die Russische Polar-Expedition das 

 Verbreitungsgebiet der Art beträglich nach Osten, beinahe zur voll- 

 ständigen Circumpolarität. Meines Wissens ist H. p. nur in der 

 Tschuktschen-See noch nicht konstatiert worden; im Beaufort-Meere 

 ist diese Art von amerikanischen Expeditionen gefunden (nach 

 Stimpson, teste Hansen)". 



