ZOOLOGY A.ND BOTANY. MICROSCOPY. ETC. 331 



Winter Plankton.*— J. Woloszynska gives an account of the winter- 

 plankton of the ponds in and near Lemberg. At - 2u° C. under a thick 

 sheet of ice there was a rich plankton. Most of the organisms contained 

 brown chlorophyll ; and the water was of a brown colour. Chloro- 

 phyceae and Cyanophycefe were poorly represented. The commonest 

 winter-plankton consists of Feridiniwn anglicum, P. aciculiferum, 

 Sphseroeca Volvox, Synura uvella, Gyclotella compta. The brown 

 colouring-matter has the power of absorbing the weak light-rays that 

 pass through the ice. 



Peridiniae of the Adriaticf— J. Schiller gives an account of some 

 new species of Peridinium from the northern Adriatic, and belonging to 

 the sub-genus Protoperidiaium. P. ovum is allied to P. quaremnse ; 

 P. Wiesneri has no affinity to any published species ; P. spinosum is 

 allied to P. adriaticum. 



Portuguese Plankton. J — L. W. Carrisso gives an account of som- 

 plankton collected in the Bay of Buarcos, on the coast of Portugal, pre- 

 ceded by a sketch of plankton-research, the views of experts, the 

 determining agents in a plankton-flora, the methods of collecting 

 material. Among the twenty species collected, the most constant were 

 Peridinium depressum and Ceratiumfusus. 



Phytoplankton of West Coast of Africa. § — L. Mangin describes 

 the phytoplankton collected by Gruvel between the Anguin Bank and 

 the south of Dakar in the spring of 1909. There were thirty-one 

 diatoms and four Peridinise. In a table the author shows the species, 

 their relative abundance, etc. The paper brings out the interesting 

 fact of the existence near the equator of species which are abundant in 

 the temperate zone. The abundance of the phytoplankton explains the 

 plentifulness of Crustacea and of the fish which feed upon them. In 

 some places the plankton is entirely of one species, Stephanopyxis turris. 

 In the Bay of Camado the plankton is less abundant, and is variable ; 

 Stephanopyxis is rare. Bacteriastrum minus and Climacodium atlanticum 

 are new species of particular interest. 



Actinoclava, a New Fossil Diatom. |1 — 0. Miiller writes on the 

 diatoms of the Turonian (middle stratum of the Upper Chalk). The 

 diatom which he finds there constitutes a new genus, Actinoclava, which 

 belongs to the sub-family Discoideas, tribe Actinodiscese. No other 

 diatom has ever been found in this stratum ; and the genus probably 

 disappeared before the Tertiary epoch. The author also calls the 

 attention of botanists to an unknown paper on Lias diatoms published 

 in a geological periodical^ by Rothpletz, who describes thimble-shaped 

 diatoms, which he places in Pyxidicula. 0. Miiller gives a short resume 



* Kosmos, xxxvi. (Lemberg, 1911) pp. 303-8 (fig.), 



t Oesterr. Bot. Zeitschr., Ixi. (1911) pp. 832-5 (figs.). 



X These de Doctor. Sciences, Coimbra Uuiv. (1911) 110 pp. (5 pis.). See also 



Bot. Centralbl., cxvii. (1911) p. 588. 



§ Act. Soc. Linn. Bordeaux, Ixv. (1911) pp. 355-62 (pi. and figs.). 



il Bar. Deutsch. Bot. Ges., xxix. (1912) pp. 661-8 (1 pi.). 



% Zeitschr. Deutsch. Geolog. Ges., xlviii. (1896) p. 910 (pis. and figs.). 



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