an apical cell dividing by oblique walls. The frond has an assimilating tissue 
consisting of about two layers of small cells while the inner tissue is composed 
of large thick-walled cells, by Witte denoted as 
a mechanical tissue. There is also a feebly 
developed conducting tissue between the large 
inner cells. 
The antheridia seem to be unknown; in the 
Danish waters they were not met with. 
The procarps arise near the border of the 
young frond and consist, according to Kyuin (1.c.), 
of a three-celled carpogonial branch and an 
auxiliary cell borne on the same cell which bears 
the carpogonial branch. The development of the 
cystocarp has not been followed, but Kyrın has given 
a drawing of a nearly ripe cystocarp and shown that 
Fig. 600. 
Euthora cristata. From Groves Flak, Eastern 
cell-rows grow out from the cystocarpial wall and Kattegat, 24.5 m. With cystocarps. Photo, 
0-9 . D ° nat. size. 
divide the gonimoblast into smaller portions. 
The tetrasporangia arise in groups in the last segments of the fronds and 
are cruciately divided; they have not been met with in the Danish waters. 
The species has been dredged in the months of May and July, always on 
stony bottom at considerable depths, consequently in water of high salinity, growing 
on the hapters of Laminaria hyperborea and L. saccharina and on Hydroids, such 
as Tubulina and Sertularia. The fronds reach a length of 1—3.5 cm. Most of the 
specimens gathered in May had procarps or more or less developed cystocarps. Ripe 
cystocarps were met with in July. 
Localities. Ke: ZF, 26.5 m, and JQ 21.5—30 m, Fladen; EV, 22.5 m and JT, 24.5 m, Groves Flak. 
Rhodophyllis Kützing. 
1. Rhodophyllis bifida (Good. et Woodw.) Kützing. 
Kützing, Botan. Zeit. 1847, p. 23, Tab. phyc. 19, pl. 50, 1869. J. Agardh, Sp. g. o. II, pars II, 1851, 
p. 388; Nageli, Neu. Algensyst. 1847, p. 234; Reinke, Lehrbuch d. allg. Bot. 1880, p. 119; Wille, 
Entwickl. 1887, p. 71, figs. 38—39; Schmitz u. Hauptfleisch (Engl. u. Prantl) 1896, p.376; Nien- 
burg, Florideenkeiml., Hedwigia 51, 1912, p. 303; Killian, Entw. Florid., Zeitschr. f. Bot. 6, 1914, 
p. 248; Kylin, Entw., 1923, p. 31. 
Fucus bifidus Good. et Woodw. Trans. Lin. Soc. Vol. III, 1795, p.159, pl. 17 fig. 1. 
Rhodymenia bifida Greville, Harvey, Phye. Brit. I, pl. 32, 1846. 
The structure and development of the frond have been described by NAGELI, 
WILLE, KırLıan and Kyrın. The tips of the dichotomous frond have a marginal 
row of apical cells, some of which, the prineipal ones, divide by alternate, oblique 
walls. The frond consists of three layers of cells, the middlemost of which is 
composed of hypha-like filaments forming a net-work with large meshes. Hyaline 
hairs were not observed. 
