Acari. 419 



Distribution; This species is also widely distributed. It was 

 discovered at Qanersoit, West-Greenland by the Swedish expedition 

 and described by Thorell; subsequently it was found in Siberia 

 by the Vegaexpedilion and described by L. Koch under the name 

 Gamasus ovalis; later it was captured at Tasersuak 1890 (W. Lund- 

 beck), Røde (Ryder's expedition) and on Iceland in 1892 (Deich- 

 mann) and in the Sarek Mountains by the author 1907, in the nest 

 of a lemming. 



The adults have not yet been discovered, only nymphæ génér- 

 antes femininæ; but we may safely presume, in my opinion, that 

 they will be found on the lemmings. 



In 1910 I suggested that Eulœlaps stabularis var. proximus Bed. 

 found by SiG. Thor on a lemming in Norway was the female of 

 E. ambulans. I have not had an opportunity of testing the truth of 

 this suggestion, which the finding of nymphæ of the latter species in 

 the nest of a lemming in the Sarek Moutains and the great similarity 

 between E. ambulans and E. stabularis rendered very probable. 



The measurements given by Berlese (length 800) do not, how- 

 ever, agree with those of the specimens I have seen (length of 

 nymphæ 900 and 1080 resp.), but the size of the species may vary 

 in different localities. 



Fam. Trombidiidæ. 



Subfam. Bdellinæ. 



Bdella Latr. 

 B. littoralis (L). 



Localities: N. E. coast of Koldewey-Island 76' 20" N. L. 13th 

 August 1907, in the crevices of a desintegrated limestone-boulder, on 

 the shore; on a sandy slope near the second camp 30th August 1907. 



Distribution: Of all the Arctic acari B. littoralis is the one which 

 is most widely distributed. 



It occurs at the coast of France, England, Norway and Sweden; 

 in the arctic region it is recorded from both West- and East-Green- 

 land, Iceland, Jan Mayen, Bear Island, Nova Zembla, Siberia and 

 Franz Joseph's Archipelago. 



In the palæarctic regions it seems to be exclusively an in- 

 habitant of the sea-shore, never to be found even at a short distance 

 from it. 



The field-notes of Mr. Johansen seem to show, however, that 

 in the arctic regions it is met with also at some distance from the 

 shore. This is a very interesting observation which, combined with 

 the fact that, contrary to the case in the palæarctic regions, there 



