ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 65 



as they have hitherto been observed as chance constituents of marine 

 plankton, they are mentioned only, together with a note of the locality 

 and a reference to the best description and a plate of each species in 

 literature. A key is drawn up for those genera which are fully treated, 

 and these include altogether 175 species. To each species is appended 

 a list of synonymy, references to literature, a description, and a short 

 note of the distribution. All but 3 species are figured, and most of 

 them are shown in several positions ; 18 of these figures of species in 

 different positions are new, and 36 species are represented by new 

 drawings ; and 3 new forms of existing species are described. 



Diatoms of the Trentino.* — V. Largaiolli gives a short report on 

 the diatoms found by him in the river Noce, which rises in the Ortler 

 group and flows into the Adige. The author has taken samples from 

 the river at three points, near its source, about half-way along its course, 

 and near the mouth. Forty-five species and varieties are recorded, of 

 which one form is new for the Trentino district, while 7 of them are 

 rare. The first sample is characterised by the presence of Ceratoneis 

 Areas, and the second by the preponderance of Gymbellce. A table of 

 the species is given, with their distribution in Trentino. 



Fossil Diatoms. f — J. Pantocsek has studied the fossil diatoms from 

 deposits in Hungary and various other parts of the world. In a short 

 paper he describes a new genus, Szechenyia, and 17 new species, and 

 figures 68 of the species described in the paper. Another and larger 

 contribution % to our knowledge of fossil Bacillarieas is published in the 

 descriptions of the species figured in his tables 1-42 of the " Atlas der 

 fossilen Bacillarien Ungarns." In the third part of that work 584 new 

 or little known species were figured, and the text is now published 

 separately. The diatoms there treated of include species from Bulgaria, 

 Russia, Moravia, and Japan, as well as Hungary. 



A New Genus of Plankton Alga3.§ — W. Schmidle describes a 

 new alga which he has found in a collection of plankton made by 

 Lauterborn at Roxheim. The alga in question is very small, 5-8 /x long 

 and about 2 ft broad. It forms a ccenobium consisting of two half- 

 moon-shaped cells, placed as a rule crosswise. Reproduction occurs by 

 cell-division, each cell dividing first across and then lengthwise. The 

 ccenobium is formed by the two pairs of the longitudinal division. 

 The alga forms the type of a new genns, Didymogenes, and is allied to 

 Aktinastrum Lag. 



Protista Plankton.|| — This paper by E, Jorgensen deals with the 

 marine plankton of the N.W. part of the coast of Norway, and is pub- 

 lished in connection with the Hydrographical and Biological Investiga- 

 tions in Norwegian Fjords. The work is divided into three sections : 



* Atti Accad. Sci. Ven. Trent.-Istr., ii. (1905) pp. 1-8. 

 t Verhandl. Ver. Nat. und Heilk. Presburg (1903) 18 pp., 2 pis. 

 % Beitr. Kenntn. Fossil. Bacillarien Ungarns. III. Pozsony (Presburg) : 

 Wigand, 1905, 118 pp. § Hedwigia, xlv. (1905) pp. 34-5. 



|| Bergens Museums Skrifter, 1905, pp. 49-113, 146-51 (2 pis.). 



Feb. 21st, 1906 F 



