SOME ROTIFERA FROM SPITSBERaEN. 321 



When swimming and hawking about in search of food, the 

 example sketched most frequently presented a lateral view. It 

 was rarely straightened, but mostly assumed the bent position 

 figured, turning the lower part of the body nearly at right angles 

 to the upper. The skin of the central body was apjjarently 

 quite without rigidity and so loose as to appear baggy. 



Length from 300 to 375 /x the variation being to some extent 

 dependent upon the length of the toes. 



Habitat. — Ground mosses. 



In the Eeport on the Antarctic Rotifera already quoted, 

 Murray (6) gives a figure and some few details of a large species 

 of rotifer apparently having a close relationship to that now 

 described, but not agreeing in every respect. As his observa- 

 tions were felt to be incomplete, he did not name his species but 

 contented himself with assigning it to the genus Pleurotrocha. 

 It would now be placed in the genus Encentrum. Notwith- 

 standing several minor divergences in our respective descriptions, 

 I think it probable that the Antarctic form is specifically iden- 

 tical with that now discovered in Spitsbergen moss. I give 

 myself therefore the honour of associating the new species with 

 the distinguished biologist of the Shackleton Expedition by 

 naming it Encentrum Murrayi. 



Mytilina ventralis brevispina (Ehrenberg). 

 Only isolated examples seen. The type form has been found 

 in several lake and pond collections made by Mr. J. M. Jessup 

 while serving on the Alaskan Boundary Survey (see Harring's 

 report (4) already cited). It has also been found by Olofsson 

 in Spitsbergen. 



Monostyla lunaris (Ehrenberg). 

 Monostyla cornuta (Miiller). 

 Lepadella patella (Miiller). 



Dead specimens of these three were found along with those 

 of the first-named species. All are included by Harring in his 

 list of Arctic si^ecies. M. lunaris is stated by him to be " abun- 

 dant and widely distributed in the Arctic." All three species 

 are recorded by Olofsson (8). 



Adineta barbata Janson. 



Adineta gracilis Janson. 



Adineta vaga (Davis). 



