No. 3] REMARKS ON NORTHERN LITHOTHAMNIA. 107 



100 — 140 p. in diameter and, in shape, intermediate between typi- 

 cally developed ones of M. farinosa and typically developed ones 

 of M. Lejolisii, or most nearly akin to those of the latter species. 

 The form greatly resembles M. minutula. The conceptacles are 

 but little larger than usual in the latter species, and also as to 

 structure they come very near to each other. However, I refer 

 this form to M. Lejolisii, because it is more incrusted with car- 

 bonate of lime than M. minutula, the cells are mostly squarish 

 and the cortical cells are found almost everywhere. Besides occur 

 several of the hyaline cells mentioned above, which are frequently 

 appearing in M. Lejolisii. 



Like M. farinosa this species seems to occur in the upper 

 part of the sublitoral region and to prefer places fairly sheltered. 

 At Fredriksvaern on the southern coast of Norway 1 found speci- 

 mens fairly well developed on dead Zostera lying loose at the 

 bottom in a depth of 7 — 10 fathoms. It is furnished with repro- 

 ductive organs throughout the year. 



Area: Norway: Nordland (Kleen)? From Espevaer south- 

 ward! Sweden: West coast! Denmark! Western Baltic! The 

 British Isles! Atlantic coast of France! The Mediterranean! The 

 Adriatic! Atlantic coast of North America: Key West of Florida 

 (Howe!) 1 ); Massachusetts (Far low, Collins!) 2 ). 



3. Melobesia minutula Fosl. 



Alg. not. (1904), p. 8. 



f. typica. 



Frond forming patches small and irregular on hydroids, com- 



The form occurring in this place is not quite certain. It appears on Tha- 

 lassia and is like an old M. Lejolisii in habit and as to the conceptacles, 

 which, however, are frequently a little smaller than usual in this species. 

 The cells, on the other hand, are a little longer than usual, up to about 

 20 /-£. The cortical cells partly approach those of M. farinosa. I have 

 found no heterocysts. I, therefore, think it to be a somewhat extreme 

 form of M. Lejolisii. 



As to the supposed occurrence of this species in Greenland, according to 

 K j e 1 1 m a n, N. Ish. Algfl. p. 137, compare Rosenvinge, Gronl. Havalg. 

 p. 781. Besides, concerning the questionable form from Spitzbergen men- 

 tioned by Kj ell man 1. c, compare below under Lithophylhtm Crouani. 



