Figs. 1—2. Suctoria gen. sp. Alive. For description see pp. 19—21. From a pond on 

 the ice, July 30, 1894. Magnified about 760 diameters (Zeiss obj. F, oc. 2; cam. 

 luc). 



Fig. 3. Margin of the same individual. Magnified 1280 diameters (Zeiss obj. F, oc. 4; 

 cam. luc). 



— 4. From a pond on the ice, July 24, 1894. Killed with Osmic Acid, stained with 



Borax Carmine. Organisms of this kind were often seen in different preparations 

 of algee from the pond on the ice. They were never seen moving. The whole 

 surface of the organisms was densely covered with sand-grains, some of which 

 were long and very refractive, looked like silica spicules of diatoms. In this 

 figure only those grains are drawn which were visible in one microspic field, 

 simultaneously with the nucleus. The cell did not appear to have any outer mem- 

 brane. Magnified 1150 diameters (Zeiss Horn. Im. ' / 1 s» oc. 2; cam. luc). 



— 5. Probably a larger individual of the same species as Fig. 4. From a pond on the 



ice, July 27, 1894. Killed with Chromo-Aceto-Osmic Acid, stained with Borax- 

 Carmine. Drawn in the same way as Fig. 4, so that only those sand-grains situ- 

 ated on the same level as the nucleus are visible. Magnified about 1000 diameters 

 (Zeiss obj. F, oc. 3; cam luc). 



— 6. Several individuals of this kind, were seen in a preparation from a lump of alga? 



floating in a channel between the floes, nearly 2 metres deep. They had a rapid 

 vibrating, flagellata-like movement, but were fixed, as it seemed, to diatoms. The 

 grains inside them were refractive with a greenish blue colour. There was appa- 

 rently a spiral-winding in the body, which became visible by the effect of the 

 Osmic Acid (see Fig. 6). The cilia were as far as could be seen in ciliatory 

 motion, but it was probably the tail which produced the vibrating flagellata-like 

 movement of the body. The length of the tail could not be decided. A vacuole 

 was very distinctly visible in the posterior end, but was never seen contracting. 

 Where the body was fixed, could not be seen, but to judge from the mouvements 

 it was on the under central part. 



Aug. 3, 1894. Magnified about 1000 diameters (Zeiss obj. CC, oc. 5, long tube ; 

 cam. luc). Length of body without tail 0027 mm. Killed with Osmic Acid. 



— 7. Globular Alga. Living. From channel between the ice-floes, Aug 3, 1894 Mag- 



nified about 460 diameters (Zeiss obj. CC, oc. 5; cam. luc). Diameter of cell 

 0'15 mm. 



— 8. Globular Alga. From same place as Fig. 7, Aug. 3, 1894. (Zeiss obj. CC, oc. 5; 



cam. luc). Diameter of cell O'll mm. 



