245 
trichogynes penetrating through the ostiole. As lo the structure of the procarps, my 
observations are so incomplete that I must content myself with referring to the figures 
without any interpretation. The bottom under the female conceptacles was composed of 
one to three layers of cells. Ripe cystocarps in good condition were not met with; 
they seem to be rather similar the tetrasporangial conceptacles. 
As will be seen from the above description, this species differs from M. Lejolisii 
principally by the structure of the polystromatic frond, by the shape of the spor- 
angial conceptacles, by the normal presence of a columella, by the two-spored 
sporangia, and seemingly by the formation and shape of the spermatia. 
Locality. Sa: On Zostera-leaves at Horsens, September 1893. 
3. Melobesia limitata (Foslie) K. Rosenv. sp. nov. 
Melobesia Lejolisii Rosanoff f. limitata Fosl., Remarks 1905 (1906) p. 102. 
In his valuable paper on the northern Lithothamnia (Remarks, 1905 (1906) 
p. 102) FostıE described a forma limitata of Melobesia Lejolisii, characterized prin- 
cipally by smoother and apparently more solid crusts, and by less crowded con- 
ceptacles, frequently a little higher and somewhat pointed or subhemispherical- 
conical, and more sharply defined. He referred to it almost all the Danish speci- 
mens noted under the species mentioned but 
growing on Algæ instead of on Zostera. In 
examining these specimens, I have found that 
they not only differ in the characters named by 
FosLiE, but that they must be regarded as 
representing another species distinct also in 
several other characters. 
The crusts have a diameter of 3—4 mm, 
sometimes they reach 5mm or more. They 
are more or less irregularly orbicular with 
lobed margin. Frequently several crusts 
are confluent. The frond may be mono- ( 
stromatic from the border to the concep- \ 
tacles, or the inner part may be distromatic 
(figs. 166, 167) or even thicker (fig. 163 D). | 
When seen from the face, the frond pre- 
sents a similar aspect to M. Lejolisii, but the Fig. 163. al 
å Melobesia limitata. A—B, marginal parts of frond, 
cells are usually somewhat longer, VIZ. seen from the face, from M; 4, before, B, after de- 
(7—)8—10,5(— 12) m broad, 11/2 to 2 times calcification and staining. C and D, vertical sections 
6 of fronds, from I, D from the central part. 350: 1. 
longer than broad. Transversal fusions 
sometimes occur. The cortical cells are longer in transversal than in radial direc- 
tion. Trichocytes usually occur; they may be cells situated under a ramification 
or ordinary intercalary cells in the radiating filaments. They usually lack cortical 
cells, but such may occasionally be produced (fig. 163 A at left). 
mi 
len! 
ALI 
d 
