244 Algae. 



a* 



Vegetation after erosion, and in these capacities often play an im- 

 portant part in the economy of the marsh. ' E. S. Gepp. 



Griffiths, B. M., The August Heleoplankton of some 

 North Worcestershire Pools. (Journ. Linn. Soc. bot. XLIII. 

 p. 423-432. 2 pl. Dec. 1916.) 



The author reports on collections of heleoplankton taken from 

 nine pools in the Kidderminster district. Marked peculiarities 

 are shown in the respective fioras. In many cases also species 

 either rare or not commonly found in the plankton of large lakes 

 were present. The pools were too small to allow of true plankton 

 being found. A large number of forms are derived from the ben- 

 thos. The pools are either 1) traversed by a considerable stream; 

 2) supplied by bottom Springs or by small streams from adjacent 

 Springs; or 3) supplied by overflow from the river Stour. An ana- 

 lysis of the collections is set forth in tabular form. The following 

 points of interest are emphasized: 1) The presence of Bacillarieae 

 other than Asterionella is probably due to the occurrence of weeds, 

 through which the plankton-net was unavoidably drawn. 2) The 

 presence of Pandorina and Eudorina in the plankton appears to be 

 correlated with comparative purity of water. 3) The presence of 

 Microcystis aeruginosa and other Myxophyceae seems to indicate 

 contamination. It occurred ab.undantly in those pools which were 

 exposed to contamination from a village or from house-drainage. 

 Another contaminated pool contained enormous quantities of Apha- 

 nisomenon Flos-aquae. 4) Two of the pools had a predominant 

 Protococcales flora. One of these is supplied by Springs, and the 

 other is derived from the River Stour. The latter contained Cru- 

 cigenia remiformis, C. apiculata, Scenedesmus Raciborskii, and Dic- 

 tyosphaerium pulchellum. 5) Peridinieae occurred in two of the 

 pools, where there was but slight contamination. 



A noteworthy feature of these heleoplankton collections is the 

 number of algae that were either very rare or not commonly found, 

 such as Microcystis ochracea Forti, Pteromonas aculeata Lemm., 

 Scenedesmus Raciborskii Wolos., Oocystis parva W. and G. W. West, 

 Crucigenia apiculata Schmidle, Tetrastum staurogeniaeform e Chodat, 

 Geminella interrupta Turpin, Ceratium Hirundella Schrank. The 

 following are new species: Pteromonas ovalis and Crucigenia reni- 

 formis. E. S. Gepp. 



Hylmö, D. E., Studien über die marinen Grünalgen der 

 Gegend von Malmö. (Ark. Botanik. XIV. N° 15. p. 1—57. 3 Taf. 

 1916.) . 



Folgende Formationen werden unterschieden: 



1. Ulothrix-Urospora-Form., im Frühling schön ausgebildet in 

 der Zone, die zeitweise trocken liegt oder nur vom Spritz wasser 

 der Wellen durchnässt wird (hier besonders Ur. mirabüis\ Ulothr. 

 pseudoflacca als Bekleidung der kleinen Steine in ruhigen Buchten). 

 Im Spätsommer tritt hier aber eine grauschwarze Calothrix scopulo- 

 rwm-Formation auf, die obengenannte verdrängend. 



2. Enteromorpha-Form., im Sommer die grösste Rolle spielend. 

 Pfähle und Steine von der Wasseroberfläche bis 1 m tief dicht be- 

 setzt. Capsosiphon aureolus geht am höchsten herauf, E. micrococca 



