ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 327 



and others, and summaries are given of any previous algal literature on 

 the district. The general character and occurrence of the algological 

 vegetation is dealt with at some length, and among other interesting 

 facts it may be noted that certain common genera of Desmids are con- 

 spicuously absent, notably those containing species of a large size. 

 Various suggestions are offered to explain the geographical distribution 

 of the flora, which is quite European. As regards the systematic part 

 ■of this paper, certain novelties are published, and critical notes are 

 appended to many of the species-names. 



Plankton of Lake Nyasa.* — W. Schmidle describes the plankton 

 (Chlorophyceas and Cyanophyceae) of this tropical African lake. 



Fresh-water Alga? from Zambesi. f — N. Wille has examined a 

 •collection of fresh-water Algge from this part and publishes a list of 

 36 species, of which eight are diatoms and one is a species of Nitella. 

 The novelties are Placoma africanum, a new form, africana, of Anabama 

 variabilis Kiitz., and Eupodiscus lacustris. Both new species are 

 figured. 



Desmids from Bridgewater (Mass.) 4 — J. A. Cushman records 

 ■66 species of Desmids from Carver's Pond, Bridge water, Massachusetts. 

 The pond covers 42 acres. After each name is a statement as to the 

 frequency or rarity of the species. 



North American Marine Algae. § — F. S. Collins publishes a much- 

 needed account of the Ulvacese of North America, in which the four 

 genera Ulva, Monostroma, Enter omorpha, and Ilea are described, in- 

 eluding together 33 species and 2G varieties. Keys to the genera and 

 ■species are given, and critical notes are appended to the diagnoses. As 

 regards references to previous literature, these are mostly confined to 

 the works of American authors ; and specimens in the principal 

 American exsiccatas are referred to by number. Three plates, con- 

 taining forty-six figures, show the microscopic structure of many of- 

 the species. 



The same author describes an algological holiday in Eastern Maine, 

 giving the habitats of certain species and recording the occurrence of 

 Plectonema Battersii and Porphyra amplissima, both new to New 

 England. Interesting details of several species are given. 



Fresh-water Algse from South Patagonia. || — 0. Borge enumerates 

 about 150 species of fresh-water alga? from this region, which is by no 

 means rich in species. This is probably owing to the salt nature of the 

 soil in many parts, the many salt lagoons, and the salt water of many 

 of the streams. Several of the common genera of Desmids are here 

 not represented at all, while Euastrum and Pleurotomium have respec- 

 tively only three and one species each. A short list is given of the 

 plankton of a lake and a lagoon. The main part of the paper consists 

 of the list of fresh-water alga? found, with the number or numbers 



* Engl. Bot. Jahrb., xxxiii. (1902) p. 1. 



+ Oester. Bot. Zeitschr., liii. (1903) pp. 89-95 (5 figs, in text). 



X Rhodora, v. (1903) pp. 79-81. 



§ Tom. cit., pp. 1-31 ; op. cit., iv. (1902) pp. 174-9. 



|| Bihang k. Svenisk. Vet.-Akad. Handl., xxvii. (1902) No. 10,40 pp. (2 pis.). 



