397 
angia were, however, thrown off. In small depth it occurs only in shaded places, 
particularly in Sertularia growing on the older parts of Fucus (serralus). 
© Localities. NS: aF, off Thyborøn 14/2 miles, 31 met. in Abietaria abietina'; aG, off Thyborøn 
19'/2 miles, 38 met., in Hydrallmania falcata; dZ, 17 miles W. */« N. of Lodbjerg light-house, 36 m; eQ, 
27m; eO, 23 m, in Abietaria abiet. and Hydrallmania fale.; aD, off Lodbjerg, 23,5 m; XR, off Orhage. 
— Sk: eV, 6 miles N. by E. of Hanstholm light-house, 22 m, in Thujaria Thuja; off Hirshals in Abiet. 
ab. (Børgesen, !). — Lf: ZS, off Kobberod; XU, W. of Oddesund. — Kn: Various places near Hirsholm, 
partly in Laomedea; KC, Krageskovs Rev; Frederikshavn; Marens Rey. — Ke: IQ, Fladen, in Abiet. ab.; 
: EV, Groves Flak; ER, Fyrbanken, east of Anholt, 28m; HY, store Middelgrund. — Km: XF, Læsø 
Rende; bK, N.W. of Auholt, 15 m, in Tubularia; BK, Tangen; BH, off Gjerrild Klint, in Tubularia. 
Ks: OU, Schultz’s Grund; GF, Sjællands Rev; D, gronne Revle; El, entrance to Isefjord: Lammefjord. 
— Sa: Bjarkes Grund; PC, between Sejero and Ordrups Nes; PF, off Refsnæs, 18—21 m, on Abiet. 
abiet. (long free filaments); MP, Falske Bolsax. — Lb: Bjornsknude by Vejlefjord; near Damgaard, 13 m, 
in Tubularia; Linderum, dG, Hesteskoen, N.E. of Als. — Sb: GS, Lysegrundene; LK, Elefantgrund; 
Kjerteminde; between Korsor and Sprogo, “22—32 fathoms” (Magnus 1872); cL, N.E, of Sprogo, 25—27 m, 
in Abietaria abietina; DN, Vengeance Grund; UF, Hov Sand; Lohals; Spodsbjerg. — Su: BQ, off Elle- 
kilde; SB, Flinterenden. — Bw: LE and UY, Vejsnæs Flak. 
General remarks on the Ceramiaceæ. 
Referring the reader to the quoted works of Scumirz and HAUPTFLEISCH and 
ÖLTMANNS for the general morphology and biology of the Ceramiaceæ, I shall here 
only advance some remarks on some special subjects, based upon observations of 
the Danish species. 
1. Number of nuelei. The cells in the majority of the species contain a single 
nucleus. In Callithamnion corymbosum the young cells contain a single nucleus, but 
at a certain distance from the top the nuclei divide without a subsequent cell-division, 
and by continued divisions of the nuclei the old cells become multinucleate, the 
nuclei being uniformly distributed over the cell. The same takes place in Callitham- 
nion tetragonum, but the said division of the nuclei begins earlier and may occur 
already in the apical cell, which often contains two nuclei in a resting stage before 
any sign of cell-division is to be seen. In both species the downward growing 
cortical filaments consist from the first of multinucleate cells. In Spermothamnion 
repens all the cells contain several nuclei, also the apical cells and the mother-cells 
of the branches. On the other hand the reproductive cells contain from the first 
one nucleus only. As far as I have ascertained, this is not realized by degeneration 
of nuclei in an originally multinucleate cell but so that the divisions of the nuclei 
do not keep pace with the cell-divisions at the transition from the vegetative to the 
fertile phase, in consequence of which the number of nuclei in the cells diminishes 
and is finally one in the young fertile cells. 
“When no host is indicated the plant was found in Sertularia pumila. 
D. K, D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd. VII, 3. 51 
