ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 207 



the narrow sense, l)ut to the Peridiiiiea;, and particularly to the Gymno- 

 diniacefi3. Nephrose/mis olivacea is discussed and its connexion with the 

 VolvocineEe is confirmed. Some new or little known Flagellatse are 

 described. The author revises the classification of the Flagellatae. 

 Important cliaracters for the separation of the Euflagellatfe from the 

 other orders of Protista is the reproduction by longitudinal division, 

 and the structure and manner of division of the nucleus. For the 

 systematic division of the Euflagellatse themselves, the nuclei are of 

 importance, as well as the symmetry of the cell and its cilia. The cell- 

 groups are of less importance. 



Plankton of the Havel.* — H. Bethge gives an account of the 

 plankton of the Prussian river Havel, in the summer of 1911. He 

 begins with a resume of previous work, describes his own methods, and 

 by means of tables he expresses his results obtained dming a month's 

 investigation. He states that it is not the temperature, bnt the weather 

 and the direction of the wind that determine the quantity of the plankton. 



Plankton on Submarine Bank.f — 0. Paulsen treats of the plankton 

 of a submarine bank situated to the south-west of the Faroes, and lying 

 at a depth of 100 metres below the surface. The author was engaged on 

 the Danish marine investigation steamer ' Thor,' and collected material 

 in May and September 1904, and in March and May 191(». The bank- 

 plankton is of a more neritic character than that of the surrounding 

 water, the latter being more oceanic. The main part of the phyto- 

 plankton is diatoms. The author discusses the hydrographical conditions, 

 the coldness of the water, the currents, etc. 



AlgBB of Styrian Springs.^ — F. Wonisch gives an account of the 

 algal flora of the Andritz springs north of Graz. The temperature of 

 the Andritzquelle varies little from 10° C. throughout the year. Hence 

 the algal vegetation maintains an almost equal abundance in summer 

 and winter. The author found forty-six species. The Chlorophyceas 

 and Diatomacete predominate. Diatoma hyemale is very frequent, and 

 forms great masses. Batrachos^permum moniliforme is very abundant in 

 spring and early summer. The Wiesenquelle contains thirty-five species, 

 including many Chlorophycege, with Conferva homhycina predominating. 



Swiss Fresh-water Algae. § — H. Limanowska gives an account of 

 the algal flora of the River Limmat, which flows into the Lake of Zurich. 

 The subjects treated in the paper are : — Historical account of river- 

 plankton ; characters of the district investigated ; methods of collection 

 and of investigation ; enumeration of the species and varieties (255 in 

 number) ; description of novelties (one species and six varieties and 

 forms) ; distribution of the species, etc. ; algological character of the 

 district, as regards Plankton, Nereids, Mud-flora ; bibliography (121 

 works). 



* Ber. Deutsch. Bot. Gesell., xxix. (1911) pp. 496-504. 



t Biol. Arb. tilegnede Eug. Warming, Kobenhavn (1911) pp. 231-9. 



X Mitteil. Nat. Ver. Steiermark, Graz, ilvii. (1911) pp. 3-10. 



§ Mitt, aus Bot. Mus. Univ. Ziirich, liv. (1911) 149 pp. (1 pi.). 



