No. 3] REMARKS ON NORTHERN LITHOTHAMNIA. 51 



f. globosa and f. alcicornis are of rather rare occurrence, the for- 

 mer only known from Magero and Altenfjord, and the latter from 

 Tromso. 



Area: Norway : From the north-eastern boundary (Maaso and 

 Karlso, Kjellman) as far as Tromso (!), and Nordland (Kleen)? 

 Iceland (Jonsson!). 1 ) 



14. LitJiothamnion tophiforme Unger. 



Leithakalk (1858), p. 21, t. V, fig. 14. 



Frond resembling L. soriferum in habit and in structure, but 

 the sporangia bisporic. 



f. sphcerica Fosl. mscr. 



Frond 4 — 7 cm. in diameter, spherical or subspherical, branches 

 erect, straight and fastigiate. 



f. divergens Fosl. mscr. 



Lithothamnion divergens Fosl. Norw. Lithoth. (1895), p. 68, t. 16, fig. 43—50. 



f. flabellata (Rosenv.) Fosl. mscr. 



Lithothamnion flabellatum Rosenv. Gronl. Havalg. (1893), p. 772, fig. 1—2! 

 Lithothamnion flabellatum f. Rosenvingii Fosl. Norw. Lithoth. (1895), p. 70, Litho- 

 thamnion glaciale f.? flabellata Fosl. Rev. Syst. Surv. Melob. (1900), p. 1 1 ; De 

 Toni, Syll. Alg. IV (1905), p. 1730. 



Syn: Lithothamnion fasciculatum Kleen, Nordl. Alg. (1874), p. 11, partim? 

 Gobi, Algenfl. Weiss. Meer. (1878), p. 22, partim? 



Lithothamnion soriferum Kjellm. N. lsh. Algfl. (1883), p. 117, partim! Stromf. 

 Algveg. Isl. (1886), p. 18, partim? Rosenv. Gronl. Havalg. (i893), p. 772! 



Lithothamnion flabellatum Rosenv. Deux. Mem. Alg. Mar. Gronl. (1898), p. 1.3! 

 Jonss. Mar. Alg. East-Greenl. (1904), p. 6! 



Lithothamnion tophiforme Fosl. Norw. Lithoth. (1895), p. 119, partim; Rosenv. 

 Deux. Mem. Alg. Mar. Gronl. (1898), p. 13! Jonss. Mar. Alg. Icel. I (1901), p. 153, 

 partim! De Toni, Syll. Alg. IV (1905), p. 1740, partim. 



When in Norw. Lithoth. 1. c. I admitted L. tophiforme (L. 

 soriferum Rosenv.) from Greenland as being identical with L. sori- 

 ferum Kjellm., I wrote on the footing that the form admitted by 

 Dr. Rosenvinge in Gronl. Havalg. 1. c. with the denomination 

 last mentioned bore sporangia four-parted. However, by the kind- 

 ness of Dr. Rosenvinge, I then had got all the material of Li- 



*) Certain specimens are known from Eyafjord (no. 182) and Hvalfjord, but 

 the species most probably also occurs at other places. 



