No. 3] REMARKS ON NORTHERN LITHOTHAMNIA. 115 



not venture to admit the species in question from that place, the 

 less so because the calcareous algae from the north-west coast of 

 North America are as yet but very little known. 1 ) 



Area: Norway: Kristiansund, N. (Ekman!), Tusteren north 

 of Kristiansund, N. (!), and at Faeo near Haugesund (!) ; Denmark 

 (Rosen vinge!); England: North-east coast: Robin Hood's Bay 

 of Yorkshire (Holmes!); Scotland: South-west coast : Kyles of 

 Bute, Arran, Seamill, Saltcoast (Batters, Holmes!). 2 ) 



2. Lithophyllum Crouani Fosl. 



Some new or crit. Lithoth. (1898), p. 17, Rev. Syst. Surv. Melob. (1900), p. 19. 



Syn : Melobesia Laminarise Cm. Fl. Finist. (1867), p. 150, partim? 



Melobesia pustulata Aresch. Obs. Phyc. 3 (1875), p. 3, partim! 



Melobesia spec. Kjellm. Spetsb. Thall. (1875), p. 4, N. Ish. Algfl. (1883), 

 p. 137? 



Lithophyllum Crouani Jonss. Mar. Alg. Icel. I (1901), p. 154! Borg. Mar. 

 Alg. Faroes (1902), p. 401! Batt. Catt. Brit. Mar. Alg. (1902), p. 97! De Toni, 

 Syll. Alg. IV (1905), p. 1788. 



The alga occurs on the stem and on the hapters of Laminaria 

 hyperborea and L. digitata. It usually grows associated with 

 Lithoph. macrocarpum, particularly on the coast of Norway, one 

 often growing over the other, but it appears in smaller number 

 than the latter. It forms crusts orbicular or suborbicular up to 

 about 2 cm. in diameter by a thickness of up to 1.5 mm., frequently, 

 however, less than 1 mm. The surface is even and sometimes 

 slightly shining. — Once I found a curious, subsimple piece of a 

 calcareous alga at Fseo near Haugesund in a depth of about 5 

 fathoms. It is about 2 cm. long and 4 mm. thick, provided with 

 young conceptacles as in Lithophyllum and recalling a small and 

 stunted Lithoph. fasciculatum (Lam.) Fosl. It proved, however, 

 to be a piece probably of a Lithothamnion (L. norvegicum?) 

 completely and firmly surrounded by a Lithophyllum much resem- 



!) There are two or three other species in the said collection from Port 

 Renfrew, but I have not yet succeeded in finding reproductive organs in 

 any specimen. 



2 ) As to a doubtful specimen from the Faeroes and a similar one from Iceland 

 perhaps belonging to this species, cp. under Phymatolithon compactum. 



