ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
75 
Sargassum.* * * § — Prof. J. G. Agardli publishes a monograph of this genus 
of seaweeds, with a description of the different forms assumed by the 
various organs. 143 species are described, of which 24 are new. The 
author classifies them under five subgenera, viz. : — PJiyllotricha, Schizo- 
phycus , Bactrophycus, Arthrophycus, and Eusargassum , founded generally 
on the form and disposition of the receptacles. Of the five subgenera, 
Schizopbycus comprises only a single species, while 93 are included in 
Eusargassum. 
New Genus of Phseosporeae.j — M. E. Bornet proposes the new 
genus Zosterocarpus , founded on Ectocarpus (Edogonium Men., which 
he separates from Ectocarpus with the following diagnosis : — Thallus 
monosiphonius ramosus ; sporangia plurilocularia divisione peripherica 
articulorum exorta, soros crustiformes orbiculares v. annuliformes in ar- 
ticulis ramulorum formantia ; cellulae singulae sporangiorum simplices 
breves haud septatse apice poro apertse. 
Prasiola and Schizogonium. — M. E. de Wildeman considers that 
it has been established that Schizogonium and Hormidium are simply 
forms of development of the same organism. The family Ulotrichese 
must therefore be reduced to the genus Hormiscia alone of the genera 
included under it by De Toni, to which should be added Prasiola , 
which the author proposes to remove from Ulvaceae, and thinks it pro- 
bable that to it will finally be referred the species at present placed in 
Schizogonium. 
Myxochaete, a new genus of Algae. § — Under the name Myxochsete 
barbata, Herr K. Bohlin describes a new species and genus of green 
algae, growing in fresh water, epiphytic on Vaucheria sessilis, and nearly 
allied to Chsetopeltis. The thallus is discoid, and usually consists of a 
single layer of cells, is invested in mucus, and each cell is provided with 
two hyaline bristles ; the branches are irregularly aggregated, and each 
cell contains a single chlorophyll-mass. 
Neomeris and Bornetella.|| — Prof. 0. Cramer describes a number 
of species of the verticillate Siphoneae, chiefly belonging to the above- 
named genera, viz. : — Polyphysa Peniculus , Botryopliora Conquerantii , 
Neomeris Kelleri , N. dumetosa , Bornetella nitida , B. capitata. 
Observation of the structure of the mantle- sheath, and of the mantle- 
caps, especially in Neomeris and in Bornetella, lead Prof. Cramer to the 
conclusion that they are formed by intussusception. By the mantle- 
cap is meant the upper deciduous, by the mantle-sheath the lower 
permanent portion of cellulose layers formed over the apical cell 
between the layers of hairs ; this last becomes at length strongly calci- 
fied ; the others are free from lime. The sporanges and spores are 
described in both these genera ; also cubical crystalloids in the cells of 
* Handl. K. Svenska Vetensk.-akad., 1889, 133 pp. and 31 pis. See Bull. Soc. 
Bot. France, xxxvii. (1890) Kev. Bibb, p. 110. 
f Bull. Soc. But. France, xxxvii. (1890) pp. 139-48 (1 fig.). 
j Bull. Soc. Belg. Microscop., vi. (1890). See Notarisia, v. (1890) p. 1035. 
§ Bib. K. Svensk. Akad. Handl., xv. (1890) 7 pp. and 1 pi. 
|| Denkschr. Schweiz. Naturf. Gesell., xxxii. (1890) 48 pp. and 4 pis. Cf. this 
Journal, 1888, p. 464. 
