90 



Habitat. The species occurs in somewhat sheltered places, 

 on a depth of 5 — 8 fathom. I met with it on rather hard but 

 somewhat clayish bottom, forming smaller banks in company with 

 L. coralloides. A couple of specimens gathered in June and Jury 

 were provided with reproductive organs in development, or bearing 

 scars after emptied conceptacles of sporangia. 



Occurrence. Found at Mandal (Wille), Drobak (Gran) and 

 at Rotvold near Trondhjem, at the latter place local but in consi- 

 derable abundance. 



Lithothamnion coralloides Crn. 



Fl. Finist. p. 151, t. 20, gen. 133, fig. 8 — 9; Spongites coralloides Alg. mar. 

 Finist. No. 2 \2 ; excl. syn. 



f. norvegica (Aresch.) Fosl. mscr. 



Lithothamnion calcareum var. norvegicum Aresch. Obs. Phyc. 3, p. 4; ex parte. 



f. subglobosa, diametro circa 3 cm., ramosissima, ramis 1 — 

 1.3 mm. crassis, subattenuatis, apicibus plerumque rotundatis. Tab. 

 16, fig. 1—11. 



f. saxatilis Fosl. mscr. 



f. lapidibus affixa vel demum interdum libera, scabriuscula, 

 ramis brevioribus, 1 — 1.8 mm. crassis, apicibus rotundatis vel sub- 

 obtusis. Tab. 16, fig. 12 — 23. 



f. australis Fosl. mscr. 



f. parce ramosa, ramis sæpe longioribus, teretibus vel subcom- 

 pressis, 1.5—2 mm. crassis. Tab. 16, fig. 24 — 31. 



f. flabelligera Fosl. mscr. 



f. ramis brevibus, flabellatim dispositis, liberis vel plus minus 

 coalitis, compressis vel subcylindricis. Tab. 16, fig. 32 — 37. 



f. subsimplex Batt. 



in Journ. Bot. 1892, p. 8; Grevillea Vol. 21, p. 23. 

 Descr. Lithothamnion coralloides f. subsimplex Batt. 1. c. 

 Fig. „ „ „ tab. nostr. 16, fig. 38—42. 



Syn. Apora polymorpha Gunn. in Act. Nidros. 4, p. 70; ex parte; t. 15, fig. 2. 

 Nullipora calcarea Johnst. Brit. Spong, and Lithoph. p. 240; ex parte; 



pl. 24, fig. 5? 

 Lithothamnion gracile Phil. in Wiegm. Arch. p. 388 ; Aresch. in J. Ag. 

 Spee. Alg. 2, p. 524? 



