Algae. 407 



phila, Dactylococcopsis pectinatellophila , and Microcystis orissica. And 

 Dr. Annandale adds notes on the Polyzoa with which these 

 algae were associated more or less symbiotically. E. S. Gepp. 



West, W. and G. S. West. A Monograph of the British 

 Desmidiaceae. IV. (London, Ray Society. 1912.) 



The fourth volume of this work consists of 194 pages of text 

 accompanied by 33 plates. It contains the remainder of the British 

 species of Cosmarium , all those of Xanthidium and Arthrodesmus, 

 and the first 41 species of Staurastrum. 



Emphasis is again laid upon the fact that the normal position 

 of the chloroplasts of desmids is axile, and as the parietal disposi- 

 tion may be independently acquired by scattered species having no 

 close relationship with each other, such a character cannot be used 

 as a basis for the Separation of either genera or subgenera. 



The character accepted as of fundamental importance in the 

 genus Staurastrum is the production of the angles of the semicells 

 into hollow processes in a large number of the species. This cha- 

 racter is therefore utilized in primarily dividing the genus into two 

 large groups. 



The following new species and varieties are described and 

 figured: Cosmarium Botrytis var. paxillosporum, C. margaritatum 

 forma subrotundata, Xanthidium tetracentrotum forma protuberans, 

 X. Orcadense, Arthrodesmus Incus var. indentatus, A. quiriferus 

 forma compacta, A. phimus var. hebridarum, A. Bulnheimii var. 

 subincus, A. subulatus var. subaequalis , A. tenuissimus forma lon- 

 gispina, Staurastrum orbiculare var. Ralfsii, St. subpygmaeum var. 

 subangulatum, St. disputatum, St. punctulatum vars. subproductum 

 and striatum, St. pilosellum, and St. inflatum. 



The following new combinations are also made: Cosmarium 

 Gayanum var. eboracense (= C. eboracense), C. conspersum var. latum 

 (= C. latum), C. Quadrum var. madagascariense (= C. Pseudobroo- 

 mei var. madagascariense), C. Quadrum var. sublatum (= C. subla- 

 tum), C. Logiense forma expansa (= C. latum var. minor), C. crenatum 

 forma Boldtiana (= C. Boldtianum), Xanthidium Smithii var. maj'us, 

 X. aculeatum var. basidentatum (= X Bribissonii var. basidenlatum), 

 Staurastrum Capitulnm var. italicum (= St. amoenum var. italicum), 

 St. Capit. var. acanthophorum (= St. amoen. var. acanth.), St. Capit. 

 var. tumidiusculum (= St. amoen. var. tumid.), St. Clepsydra var. 

 sibericum (= St. sibericum), St. orbiculare var. hibernicum (= St. 

 hibernicum), St. torlum (= Cosm. tortum), St. dilatatum var. hiber- 

 nicum (= St. sinense var. hibernicum), St. punctulatum var. corona- 

 tum (= St. altemans var. coronatum), and St. punct. var. pygmaeum 

 (= St. pygmaeum). G. S. West. 



West, W. and G. S. West. On the Periodicity of the Phy- 

 toplankton of some British Lakes. (Journ. Linn. Soc. Bot. 

 XL. p. 395-432. pl. 19. 4 text-figs. May 1912.) 



An account is given of the detailed periodicity for twelve months 

 of the phytoplankton of Ennerdale Water, Cumberland; 

 Wastwater, Cumberland; Loch Lomond, Dumbarton- 

 shire and Loch Katrine, Perthshire. Further comment is 

 made upon the periodicity of the phytoplankton of Windermere, 

 previously worked out by the authors; and incomplete accounts are 



