88 SUMMARY OF CURRENT RESEARCHES RELATING TO 



S. grande. There are very few free-swimming Protococcoidete. The 

 majority of the species of Staufastrum and Arthrodesmus are remarkable 

 for their long spines or long processes with spinate apices, and this 

 characteristic holds good throughout the entire plankton. The most 

 striking diatoms are Asterionella gracillima, Tabellaria fenestrata var. 

 asterionelloides, and forms of Surirella robusta. The plankton is richer 

 in species in late summer and autumn than in the spring. 



Phytoplankton from Brandenburg Lakes.*— E. Lemmermann con- 

 tinues the publication of his investigations into the phytoplankton of 

 the Muggelsee and other neighbouring waters. His results are first 

 presented in the form of tables or lists for each month from May to Sep- 

 tember 1897, and from June 1898 to May 1899, with details concerning 

 the temperature of air and water, the wind, the presence or absence of 

 sunshine, etc., on the specified days. Then follow deductions from the 

 tables as to the development of the plankton flora during these two 

 periods of investigation, tracing the maximum of various groups and 

 species. Finally, lists are given, arranged systematically, of all the 

 species hitherto recorded from the Muggelsee, and eleven other lakes and 

 waters. 



Plankton of Hallstatter See.f — K. von Keissler, in a paper on this 

 subject, records five species of Chlorophycere and three of Bacillariacese, 

 with indications of the seasonal distribution of each species. 



Norwegian Phytoplankton.^— C. H. Ostenfcld publishes a list of 

 43 plankton algae found by him in two lakes in the Rendalen district, 

 Lomnaessjon and Harsjon. He finds that the algae of the former lake 

 are much the same as those recorded from the forest lakes of Lappmark, 

 and include Dinobryon (which is predominant), Tabellaria fenestrata, 

 T. floeculosa and Aster ionella formosa. Myxophyceae and Peridiniacea? 

 are entirely absent, and the Chlorophyceae are rare. The phytoplankton 

 of Lake Harsjon is rather rich, and differs entirely from that of Lom- 

 naeesjon, but resembles strikingly that of Swiss lakes. The author adds 

 critical notes to tAvelve of the species recorded. 



Russian Fresh-water Algae.§— L. Iwanoff gives an account of the 

 vegetation growing in and around certain lakes, especially Lake Bologoje. 

 The first chapter of his work contains a physical and geographical 

 description of that lake, with a list of the diatoms which help to 

 compose the thick mud at the bottom. The second chapter deals with 

 the distribution of the vegetation in Lake Bologoje, and the subject is 

 treated in some detail. The third chapter contains a list of 438 alg&> 

 from nine other Russian lakes. In the fourth are given diagnoses of 

 new species, and remarks on species already existing which present points 

 of special interest. Among these may be mentioned the division of the 

 monad of Uroglena volvoz Ehrcnb., which is here described for the first 

 time. The fifth chapter is devoted to a study of 'Algae-formations,' 



* Zeitscli. f. Fischerei, xi. (1903) pp. 7.3-123 (figs, in icxi). 

 f Yerliandl. k. k. Z< ol. But. Gesell. Wicn, liii. (1903) PP- 33S-4S. 

 I Bot. Ti.lssk., xxv. (1903) pp. '235-41. 



§ V.d. biol. Station Uologoju d. Kais St. Pet. Nsifurfv., ii. (1T02) 152 pp. Sco 

 also Bot. Centralbl., xciii.(!903) pp. 379 87. 



