590 SUMMAKY OF CURRENT RESEARCHES RELATING TO 



Dinobryon TcossogoUnsis, Sphcerocystis Schroeteri and Stichoglma olivacea, 

 var. sphmrka. 



The plankton of the ponds is quite different, and has the character 

 of a pond plankton without any marked alpine tendency, the characteristic 

 forms belonging to Myxophycefe, Dinobryacete, and Peridineae. Diatoms 

 are, as in Lake Kossogol, of no special importance, with the exception of 

 Asterionella in one lake. The great difference between the plankton of 

 Lake Kossogol and that of the surrounding waters shows very clearly 

 that the hydrographical and orographical conditions of a lake are at least 

 of as great importance for the character of the plankton as its geo- 

 graphical position. 



In the rivers there is no true plankton, the samples containing only 

 a certain number of diatoms, Myxophyce^, etc., which have been floated 

 off from the banks. 



With the exception of the new and characteristic species Dinohryon 

 TcossogoUnsis and a new variety of Peridinum iimbonatum, all the forms 

 from Lake Kossogol, as well as from the surrounding waters, are well- 

 known species with wide distribution. 



New South Wales Desmids.* — G. L Playfair describes some new 

 or less known Desmids found in New South Wales. He has studied 

 these plants for the last fourteen years in three different localities, namely. 

 Collector, at the northern end of Lake George ; Moura, a private estate 

 near Parkes ; and some of the suburbs of Sydney. Up to the present 

 only two papers on the Desmidiete of New South Wales appear to have 

 been published, one by S. Berggren and the other by Raciborski. 

 The number of species recorded at present is about 350, of which 50 are 

 doubtful or require further investigation, 280 have been definitely 

 identified, and the remaining 70 form the subject of the present paper. 

 Of these 50 species and 20 varieties and forms are new. 



Pleurotaenium.t — J. A. Cushman enumerates ten species of this genus, 

 recorded from New England, and gives a key to nine of them, which he 

 divides into three groups. The species are all comparatively large 

 and conspicuous, and are easily distinguished from one another ; four 

 of them have not yet been recorded from the British Isles. All the 

 species and varieties are more or less described, and references to 

 literature are given. F. indicum has only once been recorded, and has 

 never been verified since. It is omitted from the key to the New 

 England species. It is said to have been found by Lagerheim at 

 Tewksbury, Mass. ; but though J. Cushman has examined much of the 

 material from which Lagerheim took his Desmids, he has not succeeded 

 in finding this species. 



Diatom Flora of the Roman Bath near Budapesth.|— J. Quint has 

 already treated of this subject, and gives in the present paper the result 

 of his further studies. In the introduction he deals with the collecting 

 of the material, its preparation and preservation, and his methods of 

 examination. For a mounting medium he recommends Griibler's 



* Proc. Linu. Soc. New South Wales, xxxii. (1907) pp. 160-201 (2 pis.). 



t Khodora, ix. (1907) pp. 101-6 (1 pL). 



J N6v6nyt. Kozlem., v. (1906) pp. 74-86 (6 pis.). 



