680 SUMMARY OF CURRENT RESEARCHES RELATING TO 



notes on the British species. The book is illustrated by 166 text-figures, 

 most of which are original, and as a rule the localities are mentioned 

 where the specimens figured were collected. Accurate measurements are 

 given for the most abundant and widely distributed species. Peridinese- 

 and Characese are not included in the volume, as being outside the group 

 of fresh-water algae. A frontispiece shows a reproduction of two photo- 

 micrographs of plankton material from Loch Ruer, Sutherland, and 

 Lough Neagh, Ireland. 



British Desmidiacese* — W. West and G. S. West have brought out 

 the first volume of their Monograph of the British Desmidiaceae. The 

 preface contains a short historical account of past work. The last 

 book published on the subject appeared in 1887, since which time 400 

 species and 402 varieties have been added to the British Desmid flora. 

 A full bibliographical list is followed by an Introduction, in which a 

 general description of Desmids is given, and their minute structure is 

 dealt with under the headings of cell-wall, cell-protoplasm, chloroplasts 

 and nucleus. Other subjects discussed are Variation, Locomotion, 

 Vegetative Reproduction, Asexual Reproduction, Sexual Reproduction, 

 Phylogenetic Relationships of the Desniidiacese, Occurrence and 

 Distribution, Collection and Preservation, Examination, and Specific 

 Determination. A diagram illustrates the views of the authors on the 

 phylogeny of the genera. In the systematic treatment, the arrangement 

 of the genera is based upon the scheme of evolution already published 

 by one of the authors, and upon certain recent investigations of 

 Liitkemuiler. An analytical key is given to all known genera of 

 Desmids, of which five have not been recorded from Great Britain. 

 This first volume includes twelve genera, ending with Tetmemorus in 

 Cosmarieas. One new species is described, Mesotcenium truncatim, and 

 thirteen new varieties of species already known. Keys are given to 

 several genera, including Penkim and Closterium. Under each species 

 name stands a short list of synonymy, the diagnosis, a list of British 

 localities, the general geographical distribution, and generally some 

 critical remarks. The volume is illustrated by thirty-two plates, some 

 of which are coloured. Most of the figures are original. 



West Indian Fresh-water Algse.t— G. S. West describes a collection 

 of fresh-water species found by A. Howard in the islands of Barba- 

 does, Dominica, and Trinidad. The author finds nine new species 

 among them, three of which are epiphytic on Pithophora Cleveana 

 Wittr. Of the remainder, there were several of special interest, notably 

 GlcRotcmium Loitlesbergerianum Hansg., which was remarkable on 

 account of the extraordinary deposition of black pigment in its integu- 

 ments ; and Cosmarium bireme Nordst. var. barbadense, because of its 

 minute size. The most interesting of the diatoms were Achnantlm 

 Hdrmannii Gutw., Cerataulus lewis, var. thermalis Grun., Tropidoneis 

 Van HeurcHi Cleve, and Terpsino'e muska Ehrenb. 



* Monograph of the British Desniidiacese, i. (LondoD, Ray Society, 1904) xxxvi. 

 and 224 pp., 32 pis. t Jonrn. Bot., xlii. (1904) pp. 281-294 (1 pi.). 



