No. 3] REMARKS ON NORTHERN LITHOTH AMNIA. 19 



found partly solitary, partly associated with other calcareous algae 

 and is attached to rocks or particularly to small stones or to shells 

 of mollusks. It is sometimes met with in the lower part of the 

 litoral region, but has its most frequent occurrence in the sublitoral 

 region in a depth of 5 — 15 or 20 fathoms, exceptionally deeper. 

 Thus the Danish Ingolf Expedition in 1896 brought home specimens 

 of this species picked up even from a depth of 44 fathoms at Stat. 

 127 on Lat. 66° 33', Long 20° 05' W. The alga has been col- 

 lected with reproductive organs from the month of May till the 

 month of October. 



Area: Norway: From the north-eastern boundary to Hauge- 

 sund(!); N. and E. Iceland (Strom felt, Jonsson!); the Faeroes 

 (Borgesen I) 1 ); the Atlantic coast of North America: Wood's 

 Holl, Mass. 2 ); Gloucester, Mass. (Farlow!), Eagle Island, Jaddle- 

 back Island, Me. (Collins!), Eastport, Me. (Farlow!); New- 

 foundland (Waghorne!); Ellesmereland, southere coast: Havne- 

 fjord, Exkrementbugten, Gaasefjord, Hvalrosfjord, Jammerbugten 

 (Baumann, Bay, Simmons!); Ellesmereland, east coast: Rice 

 strait (Simmons!); West Greenland (Hartz, Holm, Rosen- 

 vingef); East Greenland: Steno (Kruuse sec. Jonsson!), Dan- 

 marks island at Heklahavn (Hartz sec. Rosen vinge!); Spitz- 

 bergen: between Norskoerne and Amsterdamoen (Nils Johnsen!); 

 Lat. 80° 31', Long. 18'o (M almgreen!) 3 ); the White Sea (Gobi!). 



3. Lithothamnion fiavescens Kjellm. 



N. Ish. Algfl. (1883), p. 129, t. 6, fig. 1—7! Fosl. Contrib. 1 (1890), p. 8; 

 Fosl. Norw. Lithoth. (1895), p. 110; Jonss. Mar. Alg. Icel. I (1901), p. 153! De 

 Toni, Syll. Alg. IV (1905), p. 1739. 



In a vertical section of this species the hypothallic layer is 

 developed mainly as in Lithoth. Iceve. The cells are 14 — 40 /* 



v ) It seems very likely that this species also occurs at the northern coast of 

 Scotland. But I have not yet seen sure specimens from that place. Spe- 

 cimens recorded from the British Isles under the name L. Stromfeltii (L. 

 Iceve) have turned out to be L. Sonderi. 



2 ) Specimens seen from this place are sterile and consequently uncertain. 



3 ) According to specimens in the Riksmuseum at Stockholm, collected in 1861 

 „in 10 fathoms wather, 3 — 5 miles (geogr. ?) from nearest land." 



