220 Algae. 



Setchell, Wm. A., Regeneration among Kelps. (University of Cali- 

 fornia Publications. Botany. Vol. II. 1905. p. 139— 168. Pls. 15— 17.) 



The descriptions and figures of the regeneration processes of 

 several species of Laminaria are based entirely upon Observation, 

 no experiments having been performed. Three types of regeneration 

 are recognized, 1. Continuous Physiological Regeneration, by which 

 the tip of the stipe and base of the blade are constantly renewed 

 to make good the constant erosion at the tip; 2. Periodic Physio- 

 logical Regeneration, by which the blade is renewed in the spring; 

 and 3. Restorative Regeneration, which results from wounds. In the 

 first type, regeneration is from an inconspicuous intercalary meristem, 

 while in the other two types it is only the inner tissues which are 

 active. Charles J. Chamberlain (Chicago). 



Stiles, M. H., Yorkshire Diatoms in 190 5. (The Naturalist. 

 No. 591. London. April 1906. p. 128, 129. 1 fig.) 



This forms a Supplement to R. H. Philip's report in the 

 January number of the „Naturalist" and contains two lists, one of 

 which enumerates thirty-one species and varieties not previously re- 

 corded for Askern, among them being Philip's new variety of 

 Fragilaria capucina with a curious median inflation; this is figured 

 as var. inflata. The other iist comprises sixty-four species and 

 varieties from a small hillside streamlet at Ilkley. 



E. S. Gepp-Barton. 



West, W. and G. S., A comparative study of the Plankton 

 of some Irish Lakes. (Trans. Roy. Irish Acad. Vol. XXXIII. 

 Sect. B. Part II. April 1906. p. 77—116. Plates VI— XI.) 



This paper is a further account of the investigation by the 

 authors of the freshwater algae of Ireland. In a former paper, 

 published by the same Academy, the results were described of their 

 work on the phytoplankton ofLough Neagh and Lough Beg. 

 The present paper deals with the plankton of some of the most impor- 

 tant iakes in the W. and S. W. of Ireland and includes a tabulated 

 comparison between that and the phytoplankton of Lough Neagh 

 and Lough Beg. Algae were also collected, but these are treated 

 separately. Some of the pelagic organisms had never bcfore been 

 observed in the British Islands. 



Almost all the lakes examined were very little above sea level. 

 The authors deal with their subject under two headings: Detailed 

 account of the plankton of the loughs investigated ; and Systematic 

 account of the more important Algae of the plankton. 



Brief notes are given in the first part concerning the principal 

 features of 16 loughs with mention of any peculiarities exhibited by 

 the plankton and the dominant forms contained there in, with the 

 dates on which the material was collected. Special attention is paid 

 to the forms of Ceratiiim hlrnndinella 0. F. Müll., the abundance 

 and Variation of which is a striking feature of the freshwater plankton 

 of Great Britain and Ireland. The diversity of form is greater 

 in Ireland than in the west of Scotland, or in the Orkneys 

 and Shetlands; and it is not uncommon to have two, or even 

 three, distinct forms in one lake. Figures are given of nine variations. 



As regards the Algae, only those of special interest are men- 

 tioned in the present paper. Five new species are described: Cos- 

 marium Corribense , Stanrastruni dorsidentiferuni , Rhizof^olenia 



