234 



DK, Bolsaxeii, 13 -15 m. - Lb: XQ, off Middelfart, north side of Lyngsodde, 19 m; north of Faena Kalv. 

 — Sb : GT, near the broom at Asnses; GP off Halskov, 10 m; Avernakliage by Nyborg, sliallow water; 

 near Vresen, 7 — 9 ni (Ostenfeld). — Su : At Ellekilde Hage 11,5 m. 



Epilithon Heydrich. 



Melobesiae, Ber. deut. bot. Ges. 1897, p. 408. 



1. Epilithon membraiiaceuni (Esper) Heydrich. 



Heydrich, I.e.; Cotton, Mar. Alg. Clare Island, 1912, p. 150. 



Corallina membranacea Esper, Pflanzenk. 1786 t. 12, fig. 1-4 (not seen). 



Mclobesia membranacea Kosanoff, Melob., 1866, p. 66, pi. II figs. 13 — 16, pi. Ill fig. 1; Hauck, Meeresalg., 

 p. 265; Guignard, Devel. et const, des antheroz., Revue gen. de Botanique. I, 1889, p. 182, pi. VI 

 figs. 22-23. 



Melobesia corticiformis Kiitzing; Rosanoff, Melob. p. 76, pi. I figs. 14 — 16; Solms, Corall. p. 11, Taf. Ill F"ig. 25. 

 Lithothamnion mcmbranaceum Foslie, List of spec, of the Lith., 1898, p. 7; Remarks, 1905, p. 72. 



As to the morphology of this species reference may be made to the descrip- 

 tions of Rosanoff and Foslie, to which I liave only little to add. 



The cells of the basal layer are, as pointed out by Rosanoff (1. c. p. 67), not 

 arranged in distinct concentric zones; they are often connected through transversal 

 fusions (fig. 152 A). The frond is monostromatic in its marginal part, which may 

 be of greater or lesser extent. Otherwise the frond is often partly distroniatic, and 

 near the conceptacles it becomes gradually thicker, the cells dividing by transverse 

 walls. There is thus no distinction between hypothallium and perithallium. 



The sporangial conceptacles were often somewhat smaller than stated by Foslie, 

 viz. 110—140 // in diameter. Their outline is frequently oval, as mentioned by 

 Rosanoff (1. c. p. 76) and Mme Lemolne (in Cotton, Clare Isl. Surv. p. 150). The 



number of tlie mu- 

 ciferous canals was 

 also often some- 

 what less than that 

 found by Foslie, 

 namely 8 — 27, most 

 frequently 16—21, 

 while Foslie indi- 

 cates 20-30. No 

 relation was found 

 between the num- 

 ber of the muci- 

 ferous canals and 

 the locality. 



The sporangia 

 apparently arise 

 from the second 

 cell -layer. The 



Fig. 152. 



Epililhon niiiiibrdimcciiiii. A. Iroiid si'cn from Ijelow showing several fusions. B, letraspor- 

 angiuni not yel fully divided. C, sporangial conceptacle seen from above; a sporangium 

 is seen under the roof. Z>, vertical section of sporangial conceptacle, A,B,D345:i. C200;l. 



