60 M. FOSLIE. [1905 



on the bottom. Sterile specimens are almost undistinguishable in 

 habit from certain forms of L. nodulosum and L. norvegicum. 



The conceptacles of sporangia in L. Granii particularly occur 

 in the upper part of the branches. They are convex, partly but 

 little prominent, partly subprominent, 300 (250) — 400 jx in diameter, 

 and often as crowded as in L. topliiforme. The roof is tra- 

 versed by 30 — 60 muciferous canals. The sporangia are bisporic, 

 100 — 180 fi long, 40 — 60 p. broad. The conceptacles are partly 

 gradually overgrown, partly and more frequently falling to decay, 

 and the scars are effaced by new-formed tissue. Those of cysto- 

 carps are conical and of about the same diameter as those of 

 sporangia. 



It seems as if Lithoth. Battersii is a stunted form of this 

 species, partly attached to fragments of other calcareous algae. I 

 have only seen the specimens pictured 1. c. which are also appro- 

 aching stunted forms of L. colliculosum. It is, therefore, not sure 

 to which of these species it is referable, but at any rate it can 

 hardly be considered as independent. 



The species in question grows in the sublitoral region in a 

 depth of 3 — 15 fathoms. It occurs particularly in fjords or in 

 places fairly sheltered, where the tidals are running more or less 

 strongly. It has been found with reproductive organs in January, 

 April till September, and in December. 



Area: Norway: Skorpen in Tromso Amt(!), the Trondhjem 

 Fjord (!), the Puddefjord at Bergen (!), Haugesund(I), Fredriksvaern(!), 

 the Christiania Fjord (Gran, Schreiner !,!), Hvaloerne(I); Sweden: 

 the Gullmarfjord (Arwidsson!), Skelderviken (Lonnberg!); 

 Denmark (Rosenvinge!); Scotland: Cumbrae (Batters!); Ire- 

 land: Larne, co. Antrim (Hanna!); Dalkey Sound near Dublin 

 (Johnson!,!). 1 ) 



16. Lithothamnion vardoense Fosl. 



Vidensk. Selsk. Skr. 1905, No. 2. 



1 ) The specimens from Scotland and Ireland are young, and it is difficult to 

 distinguish them from young specimens of L. colliculosum, so that the 

 determination may admit of doubt. 



