198 KECENT LITERATURE ON FRESHWATER ALG.E. 



Conjugat(B, showing that they regard the Zygnemacece (as repre- 

 sented by the Mesocarpem and Pgxisporeai) as the most highly 

 speciaUzed famihes of the group, "the formation of the sporocarp 

 being a faint indication of an alternation of generations." It 

 may be suggested that the use of the terms " carpospores " and 

 " sporocarps " for spores of Mesocarpem requires more justification 

 than is given by the authors. 



The Botanical Gazette (vol. xxv. Feb. 1898, no. 2) contains 

 "Observations on some West American Thermal Algffi," by Miss 

 Josephine E. Tilden. These observations are based on three 

 collections made by the author in Yellowstone National Park, Salt 

 Lake City and Banff, and on algae found by Mr. W. H. Weed in 

 Yellowstone Park ; and by Prof. F. E. Lloyd in the region of the 

 Cascade Mountains, Oregon. 



Miss Tilden describes two new species and several new varieties 

 and forms. Microspora Weedii Tild. was found by Mr. Weed in 

 Yellowstone Park, the temperature of the water in which it was 

 growing beiug 49° C. The plant is described as being nearly 

 allied to M. ahbreviata Lagerh., differing from it " in being entirely 

 free from the ferruginous colour, in having a thin membrane, and 

 in its habitat." The other new species is SpiruUna cahlaria, found 

 by Miss Tilden in the Natural Sulphur Springs at Banff, Canada. 

 There are three plates, one being a photograph of Solitary Spring, 

 Upper Geyser Basin, Yellowstone Park — a weird-looking place. 

 Here Phormidmm lamiiiosum is said to form " plumy strings," 

 indeed, this species is said by Miss Tilden to be " by far the most 

 widespread and abundant of any alga in the hot waters of the 

 park." She adds that so far as she knows it is the only species, 

 except Spirulina major, that is found in both calcareous and 

 siliceous waters in this region. 



An interesting account is given by Prof. Dr. G. Ritter Beck von 

 Mannagetta, in the Botanische Zeitschrift (Jahrg. xlviii. no. 3, 

 March, 1898), " Die Sporen von Microchate tenera Thur. und deren 

 Keimung." The plant was noticed by him in a culture-glass con- 

 taining algse from the meadows bordering the Danube near Vienna. 

 Dr. Beck mistook it at first for a species of Lynghija forming 

 arbhrospores, and paid it no further attention at the time : later, 

 however, the doubtfulness of this determination caused him to 

 examine the plant carefully, with the result that he eventually 

 proved it to be MicrochcBte tenera Thur. He describes minutely the 

 formation and subsequent germination of the spores, and figures 

 the plant at all stages during the process. He is inclined to doubt 

 if this species has been rightly placed in the genus Microcha;te, 

 since he has never seen in his plant the " almost whip-like, 

 elongate, persistent, vegetative filaments," as seen in the marine 

 species M. grisea Thur. Dr. Beck considers that it would more 

 properly belong to Kirchner's genus Coleospermum. 



The first fasciculus of a Prodrome de la Flore Beige, edited by 

 E. de Wildeman and Th. Durand, which has lately appeared, 

 contains, besides the records of Mgcetozoa, the Schizophyta, Flagel- 

 lata, BiatomacecB, Co7ijugatcB (employing the name in the Westian 



