18 Algae. — Eumycetes. 



period of the year, but the various plankton-species reach their 

 maxima at different periods. 



The authors discuss the views of Whipple and Wesenberg- 

 Lund as to the great maxima of Asterionella, which occur in the 

 British lakes, and suggest that the spring and autumn temperatures, 

 being most favourable for the increase of A. gracülima play an 

 important part in the matter; they remark also that in spring and 

 autumn the available food-supply would be greatest. On the whole 

 most of the diatoms attain their greatest abundance in the autumn. 

 A few species never completely disappear from the plankton, and 

 can be found in the living State throughout the entire year. 



Few of the Myxophyceae occur in Windermere, and of these 

 Coelosphaerinm Kützingianum is the most conspicuous. 



Only two species of Peridinieae are recorded, Ceratium hirundi- 

 nella and Peridinium Willei. Seven figures of the latter species are 

 given. Three Flagellata are recorded. The authors then proceed to 

 give a systematic account of the more noteworthy species among 

 the phytoplankton of the English lakes. Of the 28 species so treated, 

 one is here described for the first time (Dinobryon crenidatum) , one 

 is new to Britain (Elakatothrix gelatiuosa), and 13 are new to Eng- 

 land. The authors append a table in which the comparative fre- 

 quency or absence of each species for each month of the year is 

 shown. E. S. Gepp. 



Cruchet, P., Excursion botanique ä Gletsch et au Gries 

 les 6, 7, 8 Aoüt 1907. Catalogue des recoltes cryptogami- 

 ques faites par M.M. D. Cruchet pasteur, Dr. med. E. 

 Mayor et par le rapporteur. (Bull. Murithienne, soc. valaisanne 

 Sc. nat. Fase. XXXV. Annees 1906—1908. p. 42—48. Sion 1909.) 



In diesem Excursionsbericht werden die parasitischen Pilze ver- 

 zeichnet, welche im Oberwallis, am Griespass und im angren- 

 zenden italienischen Val Formazza gesammelt worden sind. Es 

 sind ganz vorwiegend Uredineen. Ed. Fischer. 



Massee, G., On a new genus of Ascomycetes. (Ann. of Bot. XXIII. 

 p. 335-336. 3 figs. April 1909.) 



A new Pyrenomycete is described — named Gibsonia — , which re- 

 sembles Spumatoria Mass. & Salm, in the Hyalosporeae , but is dark 

 spored. The spores after the deliquescence of the asci are held 

 together in mucilage and pass down the long neck of the perithe- 

 cium. G. phoeospora, the Single species described, oecurred on decayed 

 masses of Saprolegniae found in a drain; spores 14 — 15-7—8 ,«. 



A. D. Cotton (Kew). 



Massee, G., The Structure and Affinities of British Tu- 

 beraceae. (Ann. of Bot. XXIII. p. 243—263. 1 plate. April 1909.) 



The author gives revised descriptions of the species of Tubera- 

 ceae hitherto found in Britain, 33 in number. Owing to their 

 subterranean habit material is very scarce and much still remains 

 to be known as to man}^ species, and also as to the distribution of 

 the group as a whole. The usual systematic sequence is followed 

 and no alterations in names are introduced. 



A short account of the structure and affinities of the group is 

 given at the beginning of the paper followed by some general 



