102 KJELLMAN, THE ALG^ OF THE ARCTIC SEA. 



of small holes perceptible to the nakecl eye. I have not seen specimens with sporo- 

 carps, uoY any with mature sporaogia. Thus I know nothing about the shape and size 

 of these. 



Relation to other species. Amoiigst the species of Lithothamuion that I know, the 

 present species exhibits the greatost resemblance to Litlwpliylluni incrustans Phil. Åresch. 

 Cp. Solms-Laubach, Corall. Monog. p. 16. In structure, however, it differs essentially 

 from this. 



Hahitat. It clothes rocky ledges to a large extent in the -upper part of the sub- 

 litoral zone, and stones and Lithothamnia in the lower part of the same region. I 

 have found it down to a depth of 15 fathoms on stony bottom. It seems to prefer 

 sheltered places. I do not know at wdiat season it bears ripe spores. The specimens 

 examined by me, were coUected at the end of June and during the latter part of July. 



Geogr. Distrib. Hitherto known only from the arctic region of the Polar Sea. 

 Its most northern place of growth is Karmak ul Bay on the west coast of Novaya 

 Zemlya, about 72° 30' N. Lat. 



Localities : The Murman Sea: in Karmakul Bay and Kostin Shar on the west coast 

 of Novaya Zemlya, in both places rather plentiful, though local. 



Lithothamnion polymorphum (L.) Aresch. 



In J. G. ÅG. Speo. Alg. 2, p. .524; Millepova polymorpha L. Syst. Nat. p. 1285; ex parte. 

 Descr. Lithothamnion polymovphura Solms-Laubach, CoralL Monogr. p. 16 — 17, siib Lithophyllo incrustante. 

 Fig. » » Hauck, Meeresalg. t. 1, fig. 4. 



Exsicc. » » Aresch. Alg. Scand. exsicc. N:o .302. 



Syn. Lithothamnion polymorphum Kleen, Nordl. Alg. p. 11, uou AuESCH. Obs. Phye. .3, p. 5, quoad 

 plantam Spetsbergensera, nec Kjellm. Algenv. Murm. Meer. p. 8, Kariska hafvets algv. p. 15. 

 I) Melobesia polymorpha Croall, Fl. Diso. p. 459. 

 » » » DicKiE, Alg. Sutherl. 1, p. 142; 2, p. 192. (?) 



Remark on the synonomy- It has been the general practice of algologists to unite 

 all or nearly all crust-like Lithothamnia into a single species, L. polymorphum. I have 

 also been guilty of this fault. Having now had the advantage of examining more 

 thoroughly a greater number of specimens, I am however perfectly convinced that 

 such a proceeding is incorrect and that there are among the crustaceous Lithothamnia 

 several well marked and easily characterized species. I have above brought into view 

 some species from the Arctic Sea, and I hope soon to get an opportunity of elucidating 

 the two or three species occurring on the west coast of Sweden, but referred by all 

 Swedish algologists to the same species, L. polymorphum. On account of the uncritical 

 treatment these plants have been subjected to, it is impossible, without having access 

 to original specimens, to determine what an author has meant by a plant called by 

 him L. ■polymorphum. A plant thus named has been reported from the American 

 Arctic Sea, but as no specimens of it have been at vay command, I refer it only with 

 hesitation to the species of L. polymorphum, as I understand it here. This is also the 

 case in some degree with respect to that Corallinea which is mentioned by Croall in 



