4 Nr. 4. L. KOLDERUP ROSENVINGE: 
phora membranifolii Lyngb. l.c. p.11 t.3B f.3. — The 
alteration of the specific name is certainly due to the fact 
that LYNGBYE now considered Ph. Brodiei a well charac- 
terized species, and the specific name alluded to the fact 
that the radiating filaments are covered by a distinct 
cuticle. GREVILLE (Alg. Brit. 1830, p. 133) pointed out that 
the joints (“granules”) of the filaments are “made up of 
three or four smaller ones”, from which it may be 
concluded that he saw the formation of tetrasporangia in 
the filaments. The hypothesis of the parasitism of these 
bodies was taken up by Sunr; he sent them, under the 
name of Rivularia rosea, to KÜTzING, who described and 
pictured them in 1843 (Phyc. gen. p. 177, Taf. 45. Fig. IV, 
1, 2) under the name of Actinococcus roseus with the 
following diagnosis: A. marinus, parasiticus roseus; cellulis 
hinc inde quadripartitis. In der Ostsee an Coccotylus 
Brodiaei und anderen Algen: v. Suhr. KÜTzING seems, 
however, to have no idea of the identity of this supposed 
parasite with the “sirothelia exacte sphaerica, laevia petio- 
lata” described in the same work p. 412 as the fructifica- 
tion of Coccotylus Brodiwi. Fig. 2 shows the cells divided 
into four, but the orientation of the cells in the tetrads is 
very variable and not in accordance with reality. J. 
AGARDH (Sp. g. o. Alg. II, 1, p. 330, 1851) describes the 
nemathecia, as these bodies were named by C. AGARDH 
(Spec. Alg. Vol. I, 1822, p. 228), and states that the joints 
of the radiating filaments develop into tetrasporangia (sphæ- 
rospore) which are cruciately divided, but he maintains 
that the plant has also “kalidia” (cystocarps) which are 
said to resemble the nemathecia very much. The existence 
of such nemathecia-like cystocarps has, however, never 
been confirmed. 
