ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 467 



two new forms are described, and certain of the more interesting species 

 are figured in the text. 



Fresh-water Algae of the East Indies.* — E. Lemmermann has 

 examined the collections of fresh-water algae made by Dr. Volz at 

 Sumatra, West Java, the Singapore Botanical Garden, the environs of 

 Bangkok in Siam, and in the Sandwich Islands. Eight new species and 

 varieties are described, and lists are given of the species found in the 

 fifteen samples taken by Dr. Volz. The flora of the tropics is compared 

 with that of Europe, and a list is given of the more widely distributed 

 forms found in the collections. 



Peroniella gloeophila.f— J. L. Serbinow has studied the structure 

 and polymorphism of this fresh-water species. He collected it on a peat- 

 bog in Finland, growing in the transparent sheaths of the Desmid 

 Hyalotheca mucosa, as well as in the filaments of Gymnozyga Brebissonii. 

 He finds that the form of the vegetative cells is of two kinds. On 

 Hyalotheca mucosa it is provided with a very long, filamentous, solid 

 stalk, the base of which is widened out to form a disc of attachment. 

 On the filaments of Gymnozyga, which has no mucilaginous sheath, 

 Peroniella has no stalk, or at the most a very short one. The structure 

 of P. gloeophila consists of a fairly thin cell-membrane, with a nucleus 

 and lamella-like chromatophores with no pyrenoids. The absence of 

 pyrenoids is, in the opinion of the author, the result of the chromato- 

 phores being formed from several distinct portions or lainelnc. Crystals 

 of calcium sulphate occur among the cell-contents. The author suggests 

 that species of Fulminaria, described by Gobi, Lagerheim, and Atkinson, 

 are merely reduced forms closely allied to Peroniella. 



Plankton of Lake Laceno.J — A. Trotter has made a study of the 

 plankton of this lake in the Avellino district, S.S.E. of Bagnoli Irpino. 

 Its area comprises about three square kilometres, and the depth is about 

 a metre and a half, except in one part, where it varies from 4-15 m. A 

 sample of benthon contained 24 species of diatoms, while the plankton 

 contained 35 species of Myxophyceas, Chlorophyceas, and Bacillariege, and 

 2 species of Peridineas. A few animals were also taken. Altogether 

 the author considers that the lake is rich in forms, both qualitatively 

 and quantitatively ; and that the general character of the plankton may 

 be described as that of stagnant water, heleoplankton. 



A New Chlamydomonas.§ — H. Bachmann publishes his second 

 paper on botanical investigations of the Lake of Lucerne. Among the 

 phytoplankton of that lake there occurs very plentifully Anabcena Jlos 

 aquce in ball-like masses. These are enclosed in a grey, felty substance 

 composed of numerous Vorticellae, and the Anabcena is very rarely seen 

 without this covering. As a regular accompaniment of these two 

 organisms, the author finds a species of Chlamydomonas, which he 

 describes here. He has not succeeded in cultivating it, on account of 



* Abh. Nat. Ver. Bremen, xviii. (1901) pp. 143-74 (1 pi.). 



t Script. Bot. Hort. Univ. Petrop, xxiii. (1905) 18 pp., 1 pi. 



t Nuov. Notar., xvi. (1905) pp. 39-53 (1 pi.). 



§ Ber. Deutscu. Bot. Gesell., xxiii. (1905) pp. 156-62 (1 pi.). 



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