NO. 16.] PROTOZOA ON THE ICE-FLOES OF TH E NORTH POLAR SEA. 19 



seen, one on each side of the "nucleus" (Figs. 18—19), /? being the larger. 

 Other small dark grains (Fig. 18, a) were seen moving slowly round in the 

 cell, and keeping near to the membrane. 



The observation was now interrupted by an accident. 



While I was studying the above organism, the organism PI. V, Fig. 7, A 

 came into the microscopic field. Thinking it was the same kind of organism in 

 an earlier stage I followed it for some time. It moved forwards by means of 

 the cilium p, and dragged a long thread or tail (h) after it, which was per- 

 haps destined to become a stalk. For some time no apparent changes took 

 place. The anterior part, somewhat resembling Fig. 1, a, was very mobile 

 towards both sides (see Fig. 1,B). I saw also another individual of the 

 same kind, but in this case the anterior part was still more loosely connected 

 with the posterior part; and it was still more mobile. At last this organism 

 disappeared entirely from sight between some diatoms. While hunting for it 

 I also came across another similar individual which was, however, less elon- 

 gated (Fig. 7, C), and with no indication of anterior or posterior parts. In 

 the interior two corpuscles or possibly nuclei (?) were, however, visible. 



SUCTORIA gen.? sp. 

 PI. VIII, Figs. 1-3. 



When this organism was first seen under the microscope, in the morning of 

 July 30, 1894, it was spheroidal tentacles like PI. VIII, Fig. 2 and with radi- 

 ating filiform tentacles. A nucleus (?) in the centre and a great vacuole («,) on 

 one side were visible. While I was observing it, it ejected at its left hand side 

 a part of its grained cellular contents (see Fig. 1). As, however, the water 

 began to diminish under the cover-glass, a fresh drop was added ; at the same 

 instant the individual contracted energically and got the appearance of Fig. 1 . 

 I could not decide whether this contraction was due to the new water, or to 

 ejection of the cellular contents. After a while it again assumed its regular 

 spheroidal form (Fig. 2). During the contraction of the animal the great va- 

 cuole, v 1 , was partly divided into three vacuoles; a similar division some- 

 times happened, when the vacuole contracted while the body had the regular 

 form. After some hours another vacuole (v*) also appeared on the other 

 side of the nucleus. It may possibly have been there before, as it was 



