252 
tacles more resemble those of M. limitata, but this species is more different prin- 
cipally by the stronger development of the filaments surrounding the ostiole. It 
much resembles M. minutula Fosl. (comp. FosLıE Remarks p. 107) from which it 
differs by its more incrusted frond and by the usual presence of trichocytes. 
Whether it can be kept distinct from it must be decided by further investigations. 
Localities. Sk: YN?, south-east of Bragerne, on Polysiphonia nigrescens and violacea, July; 
Lonstrup, on Corallina rubens, washed ashore, June (C. H. Ostenfeld). — Kn: Within Deget near Frede- 
rikshavn, on Cor. rub. (C. H. Ostenf.); north-east of Hirsholmene, 6—7,5 meters, August, (C. H. Ostenf.); 
TL, north of Læsø, on Cor. rubens, Sept.; ZL!, north of Læsø, 9,5 meters, on Corallina officinalis, July; 
TP, Tenneberg Banke, 16 met., on Cor. rubens, Sept. 
5. Melobesia minutula Foslie. 
Foslie, Algolog. Notiser, 1904, p. 8; Remarks, 1905, p.107. 
Lithocystis Allmanni Harvey, Phyc. Brit. Vol. II, plate 166, 1849 (?). 
Melobesia inequilatera Solms, Corall., 1881, p. 12, Taf. III fig. 13—18 (?). 
Non Epilithon Van Heurckii F. Heydrich in J. Chalon, Liste des Algues mar. obs. jusqu'à ce jour entre 
l'embouchure de l’Escaut et la Corogne, 1905, p. 207, fig. 1—5. 
FosLie has referred to this species some specimens growing on Bryozoans 
attached to Polysiphonia elongata collected by me in the northern Kattegat (comp. 
Remarks p. 109). They form small, scarcely incrusted fronds consisting of a single 
layer of low cells, irregular in outline but not lacunose, wherefore it has been re- 
ferred to f. typica. The frond is monostromatic in its whole extent to the border 
of the conceptacles. When seen from above, the cells are usually 7—10 £ broad, 
of the same length or a little longer. Very small hyaline cortical cells are as a 
rule present, covering the pericline walls. According to FosLie, they “mostly seem 
to be wanting”, which statement is probably founded on the fact that they are only 
discernible by rather high magni- 
fying powers, owing to their small 
size and transparence. They are 
narrower than in the other Me- 
lobesiæ examined by me. They 
were also found over the periclinal 
walls situated under the pseudo- 
dichotomies (fig. 172), a fact in ac- 
cordance with the complete absence 
of trichocytes. 
The sporangial conceptacles are 
Fig. 172. 6 6 2 0 
Melobesia minutula. A, part of a frond seen from above, at right conical-hemispherical with a small 
the primary disc. The cortical cells have not been drawn in the orifice surrounded by a whorl of 
upper and under part of the figure. B, a tetrasporangium. 350:1. re r 
cells radiating towards it. I found 
them about 90 in diameter (fig. 173). The sporangia were found to be tetrasporic 
(fig. 172 B), 43—54 » long, 24—31 u broad. FosLıE found them only disporic. — 
