14 



Thylakidiuni truncaturn Schew. 

 Body of medium size, length 70 — 110 ,tt, breadth 40 — 60 /<. 

 The specimens were typical, and contained numerous Zoochlorellae. 

 The species is very rare. 

 Habitat: Lehen (Nov.). 



Stentor Oken. 

 Of this genus, the following species were found, Stentor polymor- 

 phns, Stentor coemleus, Stentor Roselii, Stentor igneus, Stentor niger 

 and Stento?' multiformis. 



Stentor polijmor'phus Ehrbg. 



Body very large, length 900 ,« — 1,2 mm. 



The specimens did not differ from the typical, but in every case 

 they were coloured green by Zoochlorellae. It seems to be the best 

 suited for aquaria as it lives equally well in fresh or in putrid water. 

 It- was found in great numbers in an aquarium that was kept for three 

 month in the laboratory, and during this time no fresh water was added 

 to the aquarium. 



Habitat: Lehen (Oct., Nov., Dec), Universitätswiese (Dec), Deichel- 

 weir (Nov.), Zoological Garden (Oct., Jan., Febr.). 



Stentor coeruleus Ehrbg. 



Body very large, length 800 f^i — 2 mm. 



The length of this species is very variable, Johnson found speci- 

 mens which measured in extreme extension 4 mm, but he states that 

 the usual length was 2 mm. The largest specimen measured by me gave 

 only a length of 1,36 mm. 



The shape of the body is also very variable and often appears as 

 an anterior globular part with a long thin j)osterior portion. The ma- 

 cronucleus is moniliform and the nodes may be either spindle shaped 

 or oval, the latter shape is more frequently met with. It may be notet 

 here that Johnson found this species in abundance at a point in Ale- 

 wife Brook where the escape water from the pumping-station warms 

 the water to such a degree that it freezes over only in the coldest 

 weather. He found them here in every month from October to June, 

 but in July and in August, in spite of making numerous collections, he 

 failed to find any examples. 



Habitat: Lehen (Oct., Nov.), Hugstettin (Nov.), Zoological Garden 

 (Oct., Dec, Jan., Febr.). 



Steiltor Roselii Ehrb. 



Body very large, length 700 a — 1 mm. 



This species has been found by Johnson to reach 2 mm in length 



