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A SPECIES OF HYDRACARINA FOUND AT BEAR 

 ISUAND, JUNE 17th, 1921. 



the oxford university expedition to spitsbergen, 1921. 



Report No. 4. 



By Chas. D. Soar, F.L.S., F.R.M.S. 



{Read May 9ih, 1922.) 



Figs. 1 to 7 in Text. 



Through the kindness of Mr. Elton, of New College, Oxford, two 

 tubes of mites were forwarded to me for identification. In one 

 tube the mites bad been preserved in a 5 per cent, solution of 

 formalin, in the other they were in a glycerine solution. With 

 these tubes I received the following notes : 



" Found in shallow water at the edge of a large loch called 

 Ellas Lake, near the coast in the S.W. of the island, crawling 

 over stones ; their slow movements suggest they were just in the 

 process of losing the power of swimming. The size and colour of 

 these mites vary enormously. They were in all combinations of 

 reddish-brown and green ; the eyes were brilliant red. The only 

 other inhabitant of any size was a small caddis larva ; the mites 

 crawled over these without either interfering with the other. 

 The mites were in large numbers. There would appear to be very 

 few animals upon which they could be parasitic in the larval stage, 

 since they only occur in this one piece of water and there were no 

 insects except dipterous larvae — chiefly chironomids and the 

 caddis. No beetles or bugs were found at aU in the tarn, and none 

 have been recorded for any part of the island in fresh water." 



On examination I found them all to be of the same species : 

 Sperchon lineatus Sig Thor — a species described by him as found 

 in high mountain districts in cold water in Norway. 



It is curious that where this mite was found in Bear Island 

 only one species was obtained. How it arrived there in the first 

 instance can perhaps be accounted for. As far as we know, all 

 species of Sperchon deposit their ova on stones, or in the green 

 sKmy growth on stones, thus it would be quite easy for birds to 

 convey the ova on their feet from one district to another. In the 

 Bear Island collection although only one species was found it 



