NEW OR CRITICAL BRITISH ALGiE. 
23 
less flexuous, bright green, variously intertwined or sub-parallel, 
moniliform, attenuated at the apex, l*2-2'3 /x thick ; joints sub- 
quadrate, 1*2-3 /x long, protoplasm not granulose, apical cell 
sharply conical ; no calyptra. 
In shallow pools of brackish water, Point of Ayr, Flintshire. 
Ascocyclus ocellatus, like., Algenjl.,p. 46, Atlas t. 15. 
Spots from 1-6 mm. in diameter. Basal disc composed of 
concentric zones. The central portion two layers thick is suc- 
ceeded by a zone of frond composed of a single layer of cells ; 
this is again succeeded by a two-layered zone, and so on. Vertical 
filaments and sporangia arise only where the frond is composed of 
two layers. Filaments about 8 p in thickness, plurilocular 
sporangia lanceolate, stalked. 
On the fronds of Rhodymenia palmata. Weymouth ; local, but 
abundant. 
This species bears a very striking resemblance to Ascocyclus 
reptans , Bke., from which it is sharply separated by the nature of 
the basal disc. 
Myriotrichia repens, Hauck , Beitrage zur Kenntniss der AdriatescJien 
Algen , (Esterr . botan. Zeitschr., 1879, p. 242, tab. 4 ,figs. 1 and 2. 
Fronds microscopical. Filaments 200-500 /x, creeping amongst 
the cortical filaments of Mesogloece. The primary threads irregu- 
larly branched, 6-8 p thick ; joints from as long as broad to twice 
as long. The upright filaments 9-15 /x thick, simple, the apices 
ending in two or more hairs ; joints 1^-4 times longer than the 
diameter. Unilocular sporangia 20-30 /x in diameter, borne either 
on the creeping or upright filaments. Plurilocular sporangia 
clustered at the apices of the erect filaments, more or less cylin- 
drical, 30-40 fj. long, 6-9 /x broad. Unilocular and plurilocular 
sporangia borne on the same individuals. 
Weymouth. T. H. Buff ham. 
Mile. Karsakoff has demonstrated that it is unnecessary to retain 
the genus Dichosporangium, founded by Hauck, for the reception 
of this minute species. I have, therefore, retained the earlier name 
conferred on it by its discoverer. Although up to the present Mr. 
Buffham has only found a single patch of this species on 
Castagnea Griffithsiana , we may anticipate that it will be found at 
many stations around our coast, its minute size having hitherto 
protected it from discovery. 
Stilophora tuberculosa, Rke. Algenjl.,p. 72, Atlas I., 37. 
Very closely related to Stilophora rhizodes , J. A g., but coarser 
in habit and darker in colour, and the bases of the branches 
thicker. The sori are so closely placed that they touch one 
another, thus covering the whole surface of the thallus, very little 
if any of the unaltered cortical layer of the thallus being visible in 
fertile specimens. The central filaments of the sori are longer 
