ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
419 
of the male filament has formed an imperfect connection with two in 
the female, or one in the female with two in the male filament, the 
passage of the protoplasm taking place through one connecting tube 
only. 
Chlorosaccus, a New Genus of Fresh-water Algae.* * * § — Under the 
name Chlorosaccus fluidus g. et sp. n., Herr A. Luther describes a fresh- 
water alga, which he makes the type of a new genus, forming, with 
Vacuolaria , a family V acuolariace^e, intermediate between the Chloro- 
monadales and the Confervales. The following is the diagnosis of the 
genus. 
Cellulae vegetativae in coloniis gelatinosis peripherice dispositae, 
membrana tenui; chromatophori 2— piures, parietales, disciformes, luteo- 
virides, pyrenoidibus et amylo destituti ; nucleus centralis unicus. 
Divisione simultanea longitudinali cellulae filiales quaternae decussatim 
dispositae oriuntur. Multiplicatio agamica zoosporis e cellulis vegeta- 
tivis immutatis ortis, monostromaticis, ciliis binis, uno longiore 
porrecto, altero breviore, plerumque averso, germinantibus thallum 
thallo materno similem formantibus. Cellulae perdurantes akinetse 
sunt. 
Ophiocytium.j — Herr E. Lemmermann gives a conspectus of the 
20 species of this genus of Algae, three of them new, in which Sciadium 
is sunk. He ranks it as the sole member of a distinct family of Con- 
fervaceae, Ophiocytiace^e, with the following characters: — Algae uni- 
cell ulares, multis nucleis praeditae ; chlorophora plura, parietalia, saepe 
literae H ad instar formatae, epyrenoidea. The diagnosis of the genus 
is as follows : — Cellulae libere viventes v. in plantis aquaticis sedentes, 
cylindricae v. claviformes, uno polo plerumque capitato-inflatae, rectae, 
arcuatae, litterae S ad instar curvatae v. spiraliter contortae, singulae v. 
in familiis simpliciter umbellatim dispositis, v. corymboso-ramosis 
consociatae, utrinque rotundatae, truncatae v. mucronatae, v. uno polo 
rotundatae, altero stipite basi incrassato v. spina instructae ; chlorophora 
plura, parietalia, saepe litterae H ad instar formatae, epyrenoidea ; con- 
tentus cellarum globulis oleaginosis hjalinis v. flavo-fuscescentibus 
interdum praeditae. Propagatio fit aplanosporis v. zoogonidiis ovoideo- 
oblongis, biciliatis. 
XJlvella americana sp. n4 — Julia W. Snow describes a fresh-water 
alga found in an aquarium near Ann Arbor, Mich., U.S., as a new 
species of this hitherto marine genus. It has a flat disk-shaped thallus, 
and is propagated by zoospores and by vegetative division. Though 
resembling Coleochsete in appearance, it is of a much lower type of 
structure. It reverts easily to a unicellular condition. 
Coccospheres and Rhabdospheres. § — Messrs. G. Murray and V. 
H. Blackman give further details of the structure of these deep-sea 
organisms. The new family Coccosph^raceje is defined as consisting 
of free unicellular algae, provided with an outer covering of calcareous 
plates, free from, overlapping, or readily separable from each other ; 
* Bill. k. Svensk. Vet.-akad. Hand!, xxiv. (1899) 22 pp. and 1 pi. 
t Hedwigia, xxxviii. (1899) pp. 20-38 (2 pis. and 4 figs.). 
t Bot. Gazette, xxvi. (1899) pp. 309-14 (1 pi.). 
§ Phil. Trans. R.S., cxc. (1898) pp. 427-41 (2 pis.). Cf. this Journal, 1897, p. 318. 
