No. 3] REMARKS ON NORTHERN LITHOTHAMNIA. 49 



13. Lithothamnion soriferum Kjellm. 



N. Ish. Algfl. (1883), p. 117, partim ! 



f. globosa Fosl. 



Lithcthamnion soriferum f. globosa Contrib. II (1891), p. 6, pi. 3, fig. 3; 

 Kjellm. 1. c. t. 1, fig. 1 — 5; Lithothamnion tophi forme f. globosa Fosl. Norw. Lithoth 

 (1885), p. 119, partim. 



f. squarrosa Fosl. 



Norw. Lithoth. I. c. t. 21, fig. 8—9. 



f. alcicornis (Kjellm) Fosl. 



Contrib. IT (1891), p. 6, pi. 3, fig. 4; Lithothamnion alcicorne Kjellm. 1. c. 

 p. 121, t. 5, fig. 1 — 8; Lithothamnion tophiforme f. alcicornis Fosl. Norw. Lithoth. 

 p. 119. 



Syn: Millepora polymorpha Mohr, Isl. Naturhist. (1786), p. 141, 148, partim 

 t. 6, fig. b? 



Lithothamnion fasciculatum Kleen, Nordl. Alg. (1874), p. 1 1 , partim? 



Lithothamnion soriferum Stromf. Algveg. Isl. (1886), p. 18 (partim?); Fosl. 

 Contrib. I (1890), p. 6, partim. 



Lithothamnion tophiforme Fosl. Norw. Lithoth. 1. c. partim; Jonss. Mar. Alg. 

 led. I (1901), p. 153, partim! De Toni, Syll. Alg. IV (1905), p. 1740, partim. 



This species and L. tophiforme I formerly considered as 

 identical. Also Prof. Kjellm an 1. c. referred specimens of both 

 to one and the same species. They resemble each other in habit 

 and in structure. But one of them bears four-parted sporangia, 

 the other bears two-parted ones. Cp. below under the latter. 



I omit here the f. typica admitted in Norw. Lithoth. Cp. 1. c. 



pi. 21, fig. 7 and 10. It is a form intermediate between f. globosa 



and f. squarrosa, and little independent. The former seems more 



likely to be the typical form of the species, and the specimens 



pictured by Prof. Kjellm an 1. c. are most nearly connected with 



this form. 1 also leave out the f. afflnis admitted in Rev. Syst. 



Surv. Melob. p. 13. It is a very delicate form of f. squarrosa. 



In habit it even approaches young L. nodulosum or certain forms 



of L. norvegicum, but particularly a delicate L. Granii. There 



occurs a form corresponding of L. tophiforme. The form has 



risen in some localities from the use of a peculiar kind of fishing 



nets, by which coarse specimens of the alga have been crushed, 



and delicate fragments of them have continued growing. Cp. Lithoth. 



Adr. Meer. etc. p. 10. Thus it represents — at any rate partly 



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