72 M. FOSLIE. [1905 



the Orkneys (White! Traill) 1 ); the British Isles! The Atlantic 

 coast of France! The coast of Portugal ! 2 ). Morokko: Tanger 

 (Schousboe, Borne t, Kuckuck!); Alger (D e b r a y !) ; the Gulf 

 of Naples (Solms Laubach, Zool. Station!); the Adriatic: the 

 Brionic Islands (Kuckuck!). 



Subgen. Epilithon (Heydr.) Fosl. 

 List of Lithoth. (1898), p. 7; Epilithon Heydr. Melobesia; (1897), p. 408. 3 ) 



21. Lithothamnion membranaceum (Esper) Fosl. 



List of Lithoth. (1898), p. 7, Corallina membranacea Esper, Pflanzenth. (1786) 

 •t. 12, fig. 1-4. 



Descr. Melobesia membranacea Rosan. Melob. (1866), p. 66, pi. II, fig. 6—9, 

 .13—16, pi. Ill, fig. 1. 



Syn: Melobesia membranacea Lam our. Polyp, flex. (1816), p. 315! Aresch. 

 Phyc. Scand. (1846), p. 289 et in J. Ag. Spec. Alg. 2. (1852), p. 512, partim; 

 Le Jol. Liste Alg. Cherb. (1863), p. 150 partim, non Alg. mar. Cherb. no. 194! 

 Aresch. Obs. Phyc. 3 (1875), p. 3! Solms, Corall. Monogr. (1881), p. 10; Hauck, 

 Meeresalg. (1885), p. 265, fig. 104; Reinke, Algenfl. westl. Ostsee (1889), p. 31; 

 Born. Alg. Schousb. (1892), p. 188-; Debr. Cat. Alg. Maroc. etc. (1897), p. 71! 



Hapalidium roseolum Kiitz. Phyc. gener. (1843), p. 385; Spec. Alg. (1849), 

 p. 695; Tab. Phyc. XIX (1869), p. 33, t. 92 4 ); Aresch. in J. Ag. Spec. Alg. 2 

 (1852), p. 509 (sub nom. H. roseum). 



1 ) The species is mentioned by Mr. Traill 1. c. from that place as „ common 

 on sandy bottom, 4 to 15 fathoms". I have not seen specimens collected 

 by Mr. Traill which may perhaps also include L. norvegicum. But a 

 sterile specimen kept in the British Museum, collected by the Rev. Mr. 

 Whit e, no doubt belongs to this species. 



2 ) According to specimens in the British Museum without fixed locality. 



3 ) This subgenus has been based as a genus by Mr. H e y d_r i c h (Melobesise 

 in Ber. d. Deutsch. Bot. Gesellsch. 1897 p. 408), as to the vegetative part 

 on the same characters as then characterized the genus 3£elobesice, the 

 type being Lithoth, membranaceum. However, in this species the frond 

 is composed of two or more layers of cells, with the exception of the very 

 youngest parts. I, therefore, base the subgenus on the hypothallium being 

 one4ayered, as corresponding to the subgenus Carpolithon of Lithophyllum 

 and as contrasted with the hypothallium of Eulithothamnion having several 

 layers. There are, however, perhaps species which are monostromatic and 

 which should also perhaps be referred to the same subgenus. 



4 ) The alga is not found by this name in K u t z i n g's herbarium. 



