52 
NEW OR CRITICAL BRITISH ALGiE. 
the late Dr. Stroemfelt, growing on the fronds of Chorda filum. 
As the plants 1 gathered at Weymouth were thickly covered with 
sporangia, I am in hopes that the plant may prove to be not un- 
common on our shores, its minute size having hitherto protected it 
from discovery. 
Chantransia trifila, Buffham, Journ. Quekett Microsc. Club , Vol. V., 
Ser. ii., p. 24 . 
Swanage. On Cladophora (? utriculosa , Kiitz.). Aug., 1890. T. 
H. Buffham. 
This minute species, which Mr. Buffham considers is the 
smallest Floridean known, was found by him growing on an old 
specimen of a Cladophora, the fronds of which had, owing to the 
discharge of the zoospores, become hyaline, thus enabling the 
epiphyte to be studied with ease. The filaments arise, as in Ch. 
(Acrochcetivm) microscopicum, Nseg., from a single basal cell, not 
as in the remaining species of the genus, from a monostromatic disc. 
From the basal cell arise three filaments in one plane, each filament 
consisting of three or four cells about 5 p long and 4-5 p in 
diameter. Sometimes the filaments terminate in a very thin hair. 
Monosporangia, 7-8 p diam., spherical, terminal on 1-2 celled 
branches on the inner side of lateral primary filaments. Antheridia 
and cystocarps unknown. 
Flocamium biserratum, Dickie , Linn. Journal Lot. xiv.,^>. 346 . 
Swanage. Sept., 1892. 
Amongst some algae gathered at Swanage, Dorsetshire, and 
communicated to us for identi- 
fication by Miss Alridge, there 
was a specimen of this almost 
unknown species, which has, 
hitherto, been recorded from 
the Cape Verde Islands only. 
Porf. Dickie’s account (Z.c.) of 
the species is very short, and 
hardly sufficient, without a 
figure, for the identification of 
the plant, and had not his type 
specimens been preserved in 
the Herbarium of the British 
Museum, there might have 
been some doubt as to the 
identity of the British plant 
with the one from the 
Verde Islands. 
The Swanage specimens, 
which exactly agree with the 
type specimens of PI. biserratum , may be described as follows : — 
Fronds from 2-6 inches long, deep red, broadly linear, without a 
midrib; decompound pinnate, pinnae alternate or in pairs, lanceolate 
Portion of frond of Plocamium biserratum, 
Dickie, x 40. 
