ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 213 



He has also drawn up a synopsis of 47 genera and 163 species, furnish- 

 ing short descriptions of the orders, families and genera, but not of the 

 species. 



Pottia."' — C. Warnstorf publishes some studies on the genus Fottia, 

 as a preliminary to a monograph of Pottia Ehrh. (sens. str.). In an 

 introduction the author gives a general account of the distribution and 

 organization of Pottia in a restricted sense, and then deals with the 

 systematic arrangement. Material from the Berlin Botanical Museum 

 is discussed, including Gomphoneuron LorenizH Warnst., and Bidijmodon 

 argentiniensis Warnst., a new species, as well as a large number of speci- 

 mens which lack sporogonia. Pottia Macleana Rehm. is placed in 

 Pterygoneurum, and is described and figured. In a Latin key the genus 

 is divided into RhynchostegiiB and ConostegiaB, and each is further 

 divided into Gymnostoma^ and Odontostomse ; thus arranging the 

 species under four distinctly marked morphological groups. Diagnoses 

 of each species follow with critical notes, and figures of the distinguish- 

 ing characters. The circle of P. Heimii is made to include as new 

 varieties or forms six hitherto independent species. Four species are 

 sunk into P. truncata as varieties. Three new species are described. 



Mosses of North-west Germany.! — E,. Timm gives a list of species 

 new to the region of Hamburg, Schleswig-Holstein, Llibeck, and the 

 Liineburg Heath, including a few Liverworts. Fontinalis laxa Warnst. 

 is recorded in fruit for the first time. To many of the records are 

 appended notes of a morphological and biological cliaracter, notably 

 Campylopus brevipiJus, Cratoneuron decipiens, Fissidens exiUs,F.pusillus^ 

 and 2'etraplodon mnioides. OUgotrichum hercynicum is recorded from a 

 clayey ditch on the Liineburg Heath. 



Thallophyta. 



AlgSR. 



(By Mrs. Ethel S. Gepp.) 



Caledonian Phytoplankton.| — E. Telling publishes a preliminary 

 account of Caledonian phytoplankton. Wesenberg-Lund has divided 

 Europe into four regions, one of which is N. and W. Europe. The 

 author regards England as being typical of this region, as the English 

 fresh-waters contain quantitatively little, qualitatively very rich, phyto- 

 plankton. A large number of Desmids and Protococcoideoe are present, 

 a considerable Diatom flora, and a quite inconsiderable Myxophycete 

 flora. The Baltic plankton contains fewer species of algag, which almost 

 all occur in England ; the association, however, shows a quite distinct 



* Htidwigia, Iviii. (1916) pp. 35-80, 81-152 (67 figs). See also Bot. Centralbl., 

 cxxxiv. (1917) pp. 332-3. 



fAUgem. Bot. Zeitschr., xxii. (1916) pp. 17-27. See also Bot. Centralbl., 

 cxxxv. (1917) pp. 45-6. 



X Svensk. Bot. Tidskr., x. (1916) pp. 506-19. See also Bot. Centralbl., cxxxv. 

 (1917) pp. 88-4. 



