67 



call the smaller lakes, or ponds that have neither affluents nor 

 outlets "warm" lakes; the temperature of these shallow, stagnant 

 waters is in summer often comparatively high, I measured 

 15° C. in one of these very shallow ponds; in the latter the 

 ice melts early in summer; they were free from ice when we 

 arrived at the "South eastern" bay on the 20'*' of June, whereas 

 the colder lakes were still covered with ice which did not melt 

 until the last days of June. With regard to the animal life of 

 these lakes a characteristie difference was noticeable, the shallow, 

 warm lakes producing an abundant fauna; on hauling a plankton 

 net through the water small animals such as Branchinecta 

 paliidosa^ Copepoda, Cladocera, Rotifera etc. appear in great 

 numbers in the net. Notwithstanding several hauls in a couple 

 of cold lakes I obtained no micro-organisms visible to the naked 

 eye. In the lake near Jacobshavn, at the bottom of which the 

 Bryozoa occured I likewise fished in vain with my plankton 

 net; the only live animals observed were a small arctic Char 

 and a good many larve of a gnat (Chironomus) about an inch 

 long, which enclosed in their tubes of mud came up from 

 the bottom along with a tangled mass of Bryozoa, Characea 

 and moss. 



It may further be remarked that according to Rink's (I p. 39) 

 twelve years of observation the mean temperature at Jacobshavn 

 is in Jan. — 14-2, Feb. — 16-2, March —11-6, Ap. —6-7, May 



— 0-1, June +3-7, July +5-9, Aug. +4-3, Sep. +1-0, Okt. 



— 2-5, Nov. —9-1, Dec. —12-2." 



The Bryozoa proved to be Fredericella sultana Blumenb. 

 The form of the colony was the usual one with spreading 

 branches well apart from each other and much resembling 

 those 1 had seen from the abyssal region of Lake Geneva and 

 figured by Forel (1901 p. 114); the tubes contained the well 

 known brown kidney shaped statoblasts without annulus. The 

 colour of the tubes was a pale yellow, in the youngest 

 parts almost white; they lack the Diatom-coating so charac- 



