200 ' SUMMARY OF CURRENT RESEARCHES RELATING TO 



Hungarian Diatoms : Lake Balaton.* — J. Pantocsek publishes a 

 monograph comprising 288 species of diatoms from Lake Balaton in 

 Hungary, including one new genus, some 74 new species, and some 

 60 new varieties. References to literature are given for each species, 

 as well as a diagnosis in Hungarian and in Latin. The paper is illus- 

 strated by 17 plates and one text figure. In the introduction is an 

 account of the methods adopted in gathering and examining the 

 diatoms ; and a bibliography is provided. 



Pyrenoids and Elseoplasts in Diatoms.f — C. Mereschkowsky has 

 succeeded in finding pyrenoids in diatoms which partially or entirely 

 emerge from the endochrome, and may even be seen as free colourless 

 bodies on the inner surface of the chromatophores. He also finds 

 elseoplasts which arise inside the endochrome mass, from which they 

 gradually protrude, still surrounded by the endochrome and of a yellow 

 colour. The author believes that it will be possible after further in- 

 vestigations to prove a genetic connection between pyrenoids and elaeo- 

 plasts. The coloured elasoplasts are divided by the author into (1) 

 sparsioplasts which are variable in number and position, and (2) stabilo- 

 plasts which are not variable. Stabiloplasts are again divided into 

 placoplasts which are in contact with the chromatophores, and libro- 

 plasts which lie free along the middle line of the cell. Instances and 

 figures are given. 



Fossil Diatoms in Rome.:}: — Mattco Lanzi has examined dia- 

 tomaceous earth taken from the Janiculum and finds it contains 68 

 species of fresh-water diatoms and several varieties. The species are 

 those generally recorded from shalloAV water. 



The same author also enumerates 63 species of fossil diatoms, found 

 in soil which was excavated from below the Yia Nazionale, when the 

 foundations of the Banca dTtalia were being constructed. The genus 

 most abundantly represented was Epithemia, and after that the com- 

 monest forms were Navkvla radiosa, N. elliptka, Rhoicosphenia curvata, 

 Synedra longissima, and Pleurosigma attenuation. The species are such 

 as live in fresh or brackish water. 



H Diatoms of Lake Cotronia.§ — Matteo Lanzi records 86 species of 

 diatoms from this small lake. The most predominant genus was 

 Cydotella, and all the species found were fresh-water forms and princi- 

 pally floating. 



Centronella and Ph8eodactylon.|| — Knut Bohlin calls attention to 

 CentroneUa BeicheUi Voigt and points out that this organism is a near 

 ally of his PhmodactyJon tricornutwn. He therefore proposes that the 

 new genus CentroneUa be suppressed and the Bohlin species be known 

 as Phceodactylon Reichetti. He regards the plant as related to the 

 Diatomacecc. Small figures are given of both species. 



* Balaton TudoroaDyos Tamilmanyoziisanak Ercilme'nyci, ii. 2 (1902) 144 pp. 

 (17 pis., 378 figs., and 1 fig. in text). 



t Florn, xcii. (1903) pp. "7-S3 (4 figs, in text). 

 % Atti Accad. Pont. Nuovi Lincei, xlii. (1889); xlvii. (1S94\ 

 § Op. cit.. lv. (June 1902). 

 Hedwigia, Beibl., xli. (1902) pp. 209-10. 



