64 M. FOSLIE. [1905 



nodulosum. Cp. above under L. Ungeri. Fig. 1 1. c. resembles 

 specimens of L nodulosum, which I recently got from the sur- 

 roundings of Bergen where the species seems to be of frequent 

 occurrence. 



Also this species approaches several other ones. In treating 

 of L. Ungeri, I pointed out that a definite line between the latter 

 species, L. nodulosum, and L. norvegicum, can hardly be drawn. 

 They no doubt belong to the same series of forms together with 

 L soriferum. However, it is particularly L. nodulosum and L. 

 norvegicum which most nearly approach one the other. As men- 

 tioned above, young specimens of f. ty.pica are almost quite like 

 L. norvegicum f. pusilla or f. uncinata, while the older ones become 

 more densely branching and develop numerous side-branches. — 

 On the other hand, the latter specimens of this form sometimes 

 very nearly approach L. fornicatum f. apiculata and f. congregatci 

 comes near to specimens of L. fornicatum f. ob crater if or mis with 

 delicate branches. The form gracilescens is often hardly distinguish- 

 able from L. norvegicum. This is sometimes also the case as to 

 f. saxatilis, which, on the other hand, now and then is quite con- 

 sistent with L. Oranii f. reducta in habit, and only distinguished 

 by the parting of sporangia. 



L. nodulosum occurs in the sublitoral region in a depth of 

 2 — 10 fathoms. It prefers places sheltered, where the tidals are 

 running rather strongly. The alga has been found sparely fructi- 

 ferous in the months of June, July and August. 



Area 1 ): Norway: The Trondhjem Fjord, all the forms (!), 

 Hiteren, Puddefjorden at Bergen, f. saxatilis (!); the neighbourhood 

 of Bergen, f. typica (Pa lib in!); Drobak in the Christiania Fjord 

 (Gran!) 2 ) 



In Syll. Alg. IV (1905), p. 1731, De Toni records under Lithoth. Ungeri 

 Kjellm. (as considered identic with L. byssoicles Unger) „f. in Leithakalk 

 (sec. Unger)". However, Unger do not mentions his L. byssoides 

 from the „ Leithakalk", but from „der Kuste Bergens". Cp. above, and 

 Unger 1. c. p. 19 and 24. 



A few specimens from that place, about 3 — 4 cm. in diameter, seem to 

 belong to the species in question and most nearly connected with f. gra- 



