NEW OR CRITICAL BRITISH ALGiE. 
55 
marked by a narrow diaphanous band in the middle, for the most 
part semi-corticated.” 
f. divaricata. 11 Segments patent, often divaricate ; apices slightly 
forcipate, lateral branches few, for the most part simple; internodes 
in the lower part of the thallus almost naked, towards the apices 
slightly corticated.” 
f. borealis. “ Principal branches 450-650 p in diameter below, 
lateral branches of slightly different diameter, beset with sub- 
dichotomous or simple ramuli ; internodes in the lower part of the 
thallus either thinly corticated or with a narrow band, in the 
upper part and the ramuli nearly naked. 
All these forms with the exception of f. genuina are illustrated in 
the Plates, and they appear to be fairly well marked and easily 
recognisable. They may all be expected to occur on the shores of 
Britain. Of C. rubrum the author recognises no less than 10 
forms as found on the coasts of Norway ; none of them, however, 
are new to science. 
The paper is fully illustrated, but the figures lack clearness. 
En Norsk form af Ectocarpus tomentosoides , Farlow. By H. H. 
Gran (Christiania Videnskabs-Selskabs Forhandlinger for 
1893, No. 17). 
The account of Ectocarpus tomentosoides , Farlow, given by Herr 
Gran in this very interesting paper, is by far the most complete 
and accurate that has appeared up to the present time. The 
author considers his specimens belong to a new form, p. norvegicus , 
which he thus describes : — 
Fronds brownish -yellow, flaccid, up to 1 cm. high, covering the 
fronds of Laminaria saccharina with a coating of very slender 
threads. 
Primary filaments branched, creeping in the cellular membrane 
and muciferous canals of the Laminaria , secondary filaments 
arising singly or in bundles from the primary filaments, erect, 6-7 p 
in diameter, below occasionally sparingly branched, above simple or 
furnished sparingly here and there with short, divergent, secund 
ramuli. 
Cell-walls thin ; cliromatophores platter or occasionally ribbon- 
shaped, 1-3 in each cell. 
Plurilocular sporangia 50-110 p long, cylindrical, sometimes 
sparingly branched, consisting of a single row of superimposed 
cells, 6-7 p in diameter, terminal or lateral, more rarely intercalary. 
Unilocular sporangia obovate-cylindrical, occasionally pyriform, 
20-30 p long, 7-10 p in diameter, terminal or lateral on the 
shorter erect filaments, sessile, sometimes arranged in a terminal 
series of 2-4 cells. 
The form here described is the one usually found on the shores 
of the British Islands. We have seen specimens from Weymouth 
and Cumbrae, and also from Howth, in Ireland. At first the 
plant forms small roundish or oval Ascocyclus-like patches on the 
