Geology and Natural History. 4:73 



and this need is admirably supplied by Professor West's hand- 

 book. * On account of the wide distribution of most of the genera 

 described, the book will be welcome in North America as well as 

 in the British Isles. After a short introduction the author dis- 

 cusses the structural peculiarities of the algae, the methods of 

 multiplication and reproduction, the doctrine of polymorphism 

 and the various theories of phylogeny. The greater part of the 

 work, however, is filled with detailed descriptions of the British 

 genera and of the higher subdivisions, and under each genus the 

 more important species are noted or briefly described. The char- 

 acters derived from the peculiarities of the chloroplasts are empha- 

 sized throughout, and much attention is devoted to the species 

 found in the plankton of lakes and ponds. The clear and accu- 

 rate figures, nearly all of which are original, add greatly to the 

 value of the work. Professor West includes among the algae the 

 diatoms and the blue-greens, two groups which many recent 

 writers place apart ; he excludes, however, the dinoflagellates 

 and the stoneworts. Six classes are recognized : Rhodophyceoe 

 or red algae (with 6 genera), Phaeophyceae or brown algae (with 8 

 genera), Chlorophyceae or green algae (with 130 genera), Hetero- 

 kontae or yellow-green algae (with 8 genera), Bacillarieae or dia- 

 toms (with 37 genera) and Myxophyceae or blue-green algae (with 

 45 genera). The Heterokontae include a number of forms usually 

 placed among the Chlorophyceae. a. w. e. 



8. A Monograph of the British Desmidiacece y by W. West 

 and G. S. West; Vol. I, pp. xxxvi + 224; 24 colored plates. 

 London, 1904 (printed for the Kay Society). — In the last general 

 work on the British Desmids, published by M. C. Cooke in 1887, 

 290 species are described. At the present time nearly 700 species 

 are known from the British Isles, and of this number 147 species 

 are figured and described in the present volume. The introduc- 

 tory chapter is devoted to a general account of the desmids and 

 discusses the cell-structure, the variation, the methods of loco- 

 motion, the various types of reproduction, the phylogeny and 

 the geographical distribution. This is followed by an analytical 

 key to the 31 known genera, all but 5 of which are British. The 

 descriptions of genera and species which fill the remainder of the 

 volume are unusually full and accurate, and the plate-figures, 

 nearly all of which were drawn by the junior author, bring out 

 clearly the protoplasmic features of the cells and also the pecu- 

 liarities exhibited by the cell-walls. Under each species the 

 authors note the full synonymy, the measurements of the cells, 

 the known localities in the British Isles and the general geo- 

 graphical distribution ; and it is worthy of note that more than 

 half of the described species have already been reported from 

 the United States. The following 12 genera are treated in this 

 first volume: Gonatozygon (5 species), Genicularia (1 species), 

 Spirotaenia (14 species), Mesotaenium (10 species), Cylindrocystis 

 (6 species), Netrium (4 species), Penium (28 species), Roya (3 

 species), Closterium (60 species), Docidium (3 species), Pleuro- 

 taenium (9 species), and Tetmemorus (4 species). a. w. e. 



