92 
NEW BRITISH MARINE ALGAS. 
Vaucheria coronata, n.sp ., Tab. i., Fig. 1-9. 
V. (piloboloidea) antheridiis in apice ramulorum breviorum 
lateralium rectis apice truncato-rotundatis, sub-apice tubulo lato 
faecundationis proditis, e parte basilari ramuli cellula inani discretis, 
singulis vel saspius binis (uno apicali, et altero laterali vel rarius, 
ut videtur binis apicalibus) ; oogoniis singulis, subsessilibus, 
superiori parti ramuli antheridium sustinente, rarius thallo insiden- 
tibus, obovatis vel oblique obovatis, apice corona tuborum minorum 
3-6, fecundationis ornatis ; oosporis globosis vel subglobosis oogo- 
nium non plane complentibus, membrana oospori naturi crassa 
subtilissime scrobiculato-punctata. Diametr. thalli, 48-70 p; lat. 
oogon, 124-145 p, long. 145-180 /x ; lat. oospor, 116-136 p, long. 
116-145 p; lat. anther, sin. tub. faecund. 30-40 p\ crass, membr. 
oosp. ad 5 p. ” 
Bibliography. 
Studier ofver Chlorophyceslagtet Acrosiphonia, J. G. Ag., och dess 
Skandinavislca arter , af F. R. Kjellman, Med. 8 Taflor 
(Bihang till K. Svenska vet.-akad. Handlingar, Bd. 18, Afd. 
iii., No. 5), pp. 1-114. 
The genus Acrosiphonia, J. G. Ag., is adopted by Professor 
Kjellman in preference to the older name Spongomorplia, Kiitz., 
for a section of the genus Cladophora , the plants of which are 
characterized by growing gregariously in dense tufts furnished 
with root-like branches, which can act as stolons and give rise to 
new individuals, and which have the cells thinner and more 
elongated. He prefers the Agardhian name, since Kiitzing 
includes some species, e.g., C. vaucheriaformis , in his section 
Comosce , but which properly belong to Acrosiphonia. Twenty 
Scandinavian species of the genus are enumerated, of which 
number thirteen may be regarded as new, a detailed description of 
each being given. Several of these have been hitherto confounded 
under the names of C. arcta and C. uncialis. To clear up the 
intricate synonymy, as far as Scandinavian species are concerned, 
a list of the species of Acrosiphonia , occurring in the Exsiccata3 of 
Areschoug, and of Wittrock and Nordstedt (pp. 101-104) is given, 
in which they are identified with the species now described by 
Kjellman, so far as this is possible. 
Hitherto the fructification of the species of Cladophora has 
been very imperfectly known. In the genus Acrosiphonia, how- 
ever, the grouping of the species is made to depend, in the first 
place, on the character of the fertile cells, and in the second on 
the arrangement of them in the branches. 
Dr. Kjellman describes two sub-genera. In the one, Melanar- 
thrum , the zoospores are minute and very numerous, and so densely 
packed as to render the fertile cells opaque ; in the other, Isochrous , 
the zoospores are larger and laxly disposed in the fertile cells, 
which are consequently not opaque. The first sub-genus is divided 
