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62 ATLAS DEUTSCHKR MEERESALGEN.
of the vertical filaments, while the plurilocular are formed higher
up on the same filaments, by the transverse elongation and
septation of certain of their cells.
Three plates are devoted to Desmotrichum Kiitz. One species,
D. scopulorum, is new.
The specific value of the form Scytosiphon pygnicBus Kke. (plate
14), seems to be doubtful.
Ascocydus Magn. is a genus connecting Ectocarpus vfith. Myrionema,
and its species have hitherto been placed in one or other of the
latter genera. This genus, though founded so long ago as 1874,
is not given among the synonyms in Hauck. Five species ai'e here
described and figured, of which two are new.
Of Ectocarims, four species are given, one of which, E. repens
Eke., is new, and connects this genus with Ascocydus. It should
be mentioned that Dr. Keinke defines Ectocarpus, so as to include
both Strebloneina Derb. et Sol., and Pilayella, Bory.
As regards the Phaeospore* generally, the author after separating
the Cutleriacefe, Tilopteridese, and Laminariacete, unites all the
rest into a single family the Ectocarpaceae, which group themselves
about the genus Ectocarpus. He has found it impossible to break
up this great family without resorting to minute and artificial
divisions. The Ectocarpaceae are, it is true, arranged in groups
for convenience, but these groups merge into one another. On
page 87 of the ' Algenflora ' a scheme of the relationships of the
various Ectocarpaceous genera is given.
Of the Florideae only two are figured in this part. Rhodochorton
chantransioides Eke. is a new species, remarkable for its very long,
spiral chromatophores. A Baltic form of Antithamnion horeale,
Gobi, is also included.
There are one or two points of interest among the few Chlorophyceae
given. BUistophysa rhizopus Eke. is a very curious plant,
bearing a certain general resemblance to some stages of Butrydium,
but not known for certain to form zoospores. Its reproduction, so
far as is known, is by vegetative division simply.
Cladophora pygmaa Eke. is a new, and apparently insignificant
species of that enormous genus.
Epidadia Fliistrce Eke. is the type of a new confervaceous genus,
possibly not distinct from Entodadia, already established by the
author. It consists of much branched filaments, adherent to the
surface of the Flustra, and cohering to form a pseudoparenchymatous
disc. The reproduction is by zoospores formed in abundance
in each cell. It will be remembered that Entodadia Eke.
grows in the thickness of the cell-wall of various Algae.
Prhif/sheiwia scntata Eke. represents a new genus, doubtfully
referred to the UlvaceaB, with which it seems to have very little
in common. In habit it resembles a Coleochaete, but has no bristles.
It is epiphytic on various Algae and has a marginal growth, its cells
branching, and then dividing. Eeproduction is of two kinds.
1. Asexual. Here a few biciliate niacrozoospores are formed in
each of the more central cells of the thallus. They escape by a
crevice in the cell-wall. 2, Sexual. Here a larger number of