94 



and with conceptacles (of sporangia?) in development in the former 

 half of September. On the southern coast it bears reproductive 

 organs, especially sporangia, in July and December, partly mature 

 partly in development. Summer- and winter-specimens from Helgo- 

 land are partly furnished with sporangia partly with spermatia (and 

 carpospores?). On the coast of Britain it develops reproductive 

 organs in February and on the coast of France in May, but pro- 

 bably also at other seasons of the year. 



Occurrence. In the sense here taken the species has not with 

 certainty been found farther to the north than Honningsvaag in 

 West-Finmarken, and here apparently rare ; Skorpen in Kvsenangen, 

 local and scarce (f. tuberculata) ; Lyngo near Tromso, local but 

 pretty plentiful (f. valida); the coast of Nordland, common, accor- 

 ding to Kleen 1. c; Sulen in Sogn (Bo ye); Hvitingso; Mandal 

 (Wille); and Nesodden in the Christiania-Fjord, a solitary specimen 

 (Schreiner). It probably is more commonly dispersed along the 

 western and south-western coast. 



Oeogr. Distribution. The Bahusian coast of Sweden (Are- 

 schoug); Iceland (Stromfelt); Britain (Batters); Helgoland 

 (Kuckuck); France (Crouan, Bornet). The form quoted by 

 Hauck 1. c. from the Adriatic Sea very likely is L. incrustans 

 Phil. Cp. under this species. 



Lithothamnion incrustans (Phil.) Fosl. mscr. 



Lithophyllum incrustans Phil, in Wiegm. Arch. p. 388; Solms Laub. Corall. p. 16. 



f. depressa (Crn.) Fosl. mscr. 



Lithothamnion depressum Crn. Fl. Finist. p. 151. 

 Descr. Lithophyllum incrustans Solms Laub. 1. c. 

 Fig. Lithothamnion incrustans f. depressa tab. nostr. 18, fig. 10 — 11. 



f. Harvey i Fosl. mscr. 



Descr. et Fig. Melobesia polymorpha Harv. Phyc. Brit. pi. 345, 

 Fig. Lithothamnion incrustans f. Harveyi tab. nostr. 18, fig. 12 — 15. 



Syn. Nullipora polymorpha Johnst. Brit. Spong. and Lithoph. p. 238; ex 

 parte; pi. 25, fig. 2—3? 

 Melobesia polymorpha Harv. Man. p. 108; ex parte. 

 Spongites confluens Kiitz. Spec. Alg. p. 698; Tab. Phyc. 19, t. 97; 

 Aresch in J. Ag. Spec. Alg. 2, p. 519. 



