ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 407 



1918, 138, 184).* The lake, the Tovelsee, whose waters are coloured a 

 tine red by the peridinian Glenodinium pulvis-ehas Stein var. aculeatvs 

 Larg'., lies 11G2 m. high, at the foot of the Brenta group. Its greatest 

 depth is 50 m., and it is probably a stagnant lake. G. ptdvis-eleas 

 occurs in masses, but only in the comparatively warm parts, and only 

 in the warm season. In the morning the lake looked greenish ; and 

 the water was clear where it had been red the previous day. In these 

 parts the bottom was covered with a red sediment, formed by close 

 masses of Glenodinium in the lowest strata of water. As the lake 

 gradually emerged from the shadow of the mountains, so the organisms 

 rose in thick clouds to the surface and became very closely packed. 

 The cause of this vertical migration is at present unknown. E. S. G. 



Polish Fresh-water Peridiniese. — J. Woloszynska {Bull. Acad. 

 Sci. Cracovie CI. sci. math. Ser. B., 1915, 260-85, 5 pi. : Cracowie, 

 1910; see also Bot. Centralbl, 1918, 138, 171). New genera are 

 described and figured. From a careful study of the fresh-water 

 Peridiniege the author finds that the plate-shaped structure of the 

 envelope is a far more common character throughout the whole group 

 than has hitherto been allowed. In Glenodinium polonicum, one of the 

 new species, the membrane is covered with many regularly arranged 

 small warts, developed more strongly on the hypovalve. Each of these 

 forms a thickening in the middle of a small plate of regular hexagonal 

 outline. This structure of the envelope is the original one. Adapta- 

 tion of the organisms to different conditions of life brought about a 

 change of the structure of the envelope, the plates combining into 

 larger ones of less regular outline. Glenodinium is certainly the original 

 type of many genera of higher Peridiniaceai. Many of the new species 

 here described are remarkable for their beauty of structure. Gonyaulax 

 polonica, a new species, and G. apiculata Penard, from the Lakes of 

 Geneva and Balaton, are the only representatives of the genus in 

 Europe. E. S. G. 



Phytoplankton of the Dobrostany Ponds. — M. Kocz'wara {/Cosmos, 

 1915, 40, 2ol-75, 1 pi. 1 text tig. : Lemberg, 1916 : see also Bot. 

 Centralbl., 1918, 138, 181). The ponds in question are those of 

 Debrostany, Bialogorski, and Wolicki in Galicia. They were under 

 observation between 1912 and July 1914. The results are set forth in 

 tabular form and embrace Flagellates, Peridinieae, Cyanophycete, Chloro- 

 phycese, Conjugat^e, and Diatomacese. The ponds may be designated 

 Flagellate ponds. New species and varieties of Flagellates are described 

 and figured. E. S. G. 



Investig-ations of the Phytoplankton and of the Progressive 

 " Gyttja " and other Mud Formations below the Pelagic Region 

 in certain Archaic Mountain Lakes of South and Central Sweden. — 

 E. Naumann {K.Svenslc. Vetenskap. Handl., 1917, 56, 165 pp., 7 pis., 

 figs, in text ; see also Bot. Centralbl, 1918, 138, 200-3). The lakes 

 in question were situated in the primitive mountains, poor in lime, of 

 South and Central Sweden. The objects of the investigation were : — 

 (1) to use the planktology of these waters as an index of the general 



