ZOOLOGY AND BOTANY, MICROSCOPY, ETC 71 



New Genus of Polyblepharidse.* — P. A. Dangeard describes a 

 new genus of Algae, represented by one species, Stephanoptera Fabreee, 

 found in a culture in the laboratory at Concarneau. It belongs to 

 Polyblepharide.e. which hitherto has contained only two genera. A 

 description is given of the alga, and of its method of division. As a 

 rule the two individuals resulting from a division are of equal size, but 

 sometimes the inequality is so great as to give the impression of budding ; 

 this is an extremely rare phenomenon in Flagellates or Algae. At the 

 time of division each half retains one of the old flagella, and the second 

 is pushed out like a protoplasmic prolongation by the side of the first. 

 Development is terminated by an encystment ; the cell rounds itself 

 into a sphere and becomes surrounded by a very resistant membrane. 

 The cysts enclose a single nucleus as a rule, though some have two. 

 The new genus is distinguished from the two others of the family by 

 the reduction of the number of flagella to two. It shows a remarkable 

 adaptation to a medium saturated with sea-salt, while the other species 

 are fresh-water. Bipartition begins at the anterior part of the cell, 

 while in Polyblepharis and Pyramimonas it begins at the posterior part. 

 As regards the binucleate cysts, the author suggests that they may 

 present phenomena of sexual autophagy similar to those that he has 

 recently described in the Moms forms of Anthophysa vegetans. 



Phytoplankton of the Caspian Sea.j — A. Henckel gives a pre- 

 liminary list of phytoplankton from the Caspian Sea, in which he 

 enumerates 20 species. He collected 120 samples from different parts 

 of the Sea, and proposes to publish a full account of the collection later, 

 with plates. The present note is in Russian. 



Thorospha3ra4 — 0. H. Ostenfeld describes a new genus of Coecolitho- 

 phoridae which he names Thorosphsera, discovered by him between 600 

 metres and the surface of the sea, south of Cape Spartivento. He de- 

 scribes and figures the organism, which he places near Sycosphsera. 

 It is characterized by a remarkable formation of coccoliths, which act as 

 a floating apparatus. 



Plankton-alga?. § — E. Lemmermann continues his contributions to 

 the study of plankton algas. No. 26 is an account of the phytoplankton 

 -of Paraguay, founded on material collected by Herzog at Medanos. 

 It contained almost pure phytoplankton : Peridinere were absent and 

 Flagellates were very scarce. The author treats the subject from all 

 points of view. No. 27 describes plankton-algas from the Schliersee, 

 collected by Zacharias. No. 28 on Dinobryon sociale Ehrenb. No. 29 

 contains a description of a new species, Dinobryon inflatum, from a 

 small lake south of Bysjon in Sweden, and a new variety of Cosmarium 

 Novse-Semliae Wille var, sueckum. No. 80 contains a description of 

 Peridininm trochoideum formerly placed in Glenodinium. 



* Comptes Rendus, cli. (1910) pp. 991-3. 



t Script. Bot. Hort. Univ. Imp. St. Petersburg, xxvi. (1910) pp. 53-6. 

 % Ber. Deutsch. Bot. Gesell.-, xxviii. (1910) pp. 397-400 (figs.). 

 § Archiv f. Hydrobiol. u. Planktonkunde, v. (1910) pp. 291-338. See also 

 Hedwigia, 1. (1910) pp. (100-1). 



