they were in all cases, when examined, empty and more or less destroyed. I found 
sporangial conceptacles 300 or somewhat more in diameter. 
On stony bottom in 10—21 meters depth, usually associated with Corallina 
officinalis, in some places abundantly. Only found in the Samsø area. 
Localities. Sa: KI, south of Hjelm; PH, Lindholms Dyb; east of Samsø (Lofting); Stenpladen 
off Sletterhage (G. Winther); BE and BF off Sletterhage. 
Fig. 143. 
Lithothamnion norvegicum. A, axile longitudinal section of branch. B, part of a similar section near the top. C, 
part of axile longitudinal section of frond. The upper part of the tissue was deeper stained by hæmatoxyline than 
the under part. The fusion canals with the over-lving cells appear as round figures. D. transverse section of the 
central tissue of a branch. E, cell-rows from the periphery of a section of a branch. F, cells with starch grains. 
A 31:1; B—D 350:1; E, F 560:1. 
6. Lithothamnion calcareum (Pallas) Aresch. 
J. Areschoug in J. Agardh, Sp. g. o. II, 1851, p. 523. Foslie, Lith. Adriat. Meeres u. Marokko, Wiss. 
Meeresunt. VII. Heft 1, 1904, p. 13 and 32, Tafel II; Remarks, 1905, p. 67; Mme P. Lemoine, Repar- 
tition et mode de vie du Ma£rl (Lithothamnion calcareum) aux environs de Concarneau (Finistere), 
Annales de l’Institut océanographique, tome I, fasc. 3, 1910; Structure, 1911, p. 102. 
Millepora calcarea Pallas, Elench. Zooph. 1766, p. 265. 
- Lithothamnion coralloides Crouan, Flor. Finist., 1867. p. 151, pl. XX no. 133. 
This species has been found in a few localities, in particular in the eastern 
Kattegat, but always only in loose specimens without or with imperfectly developed 
conceptacles. It is, as elsewhere, rather variable. The Danish specimens have been 
referred by FosLie to the following forms. 
1. F. squarrulosa Foslie, Lith. Adr. Meer. Taf. II fig. 1—4; Lemoine, Répart. du 
Maer] fig. 1, 5, 14, Structure pl. I, fig. 5. To this form approaches f. corallioides 
(Crouan) Foslie, Norw. Lith. p. 62 pl. 16 figs. 24—25, 27-31. — This form has terete 
branches spreading in all directions. 
2. F. compressa (M’Calla) Foslie, On some Lithothamnia, 1897, p. 9, Lith. Adr. 
