181 



The conceptacles of sporangia are quoted by Hauck 1. c. to 

 be ,,sehr flach". This is not the case in a specimen from his 

 herbarium that I have seen, but fully according with those of the 

 typical form. Another specimen from his herbarium perhaps be- 

 longing to this species and most nearly related to the below men- 

 tioned specimen from the Black Sea is nearly covered with another 

 Lithothamnion, that I suppose to be a younger L. incrustans f. 

 depressa and mentioned under this. On tile other hand Hauck's 

 plant probably also includes the above f. sublævis. 



As remarked by Ros an off Le. the cystocarpic conceptacles 

 appear frequently in the same individual as those -of sporangia, 

 but either most often in the greatest number. They are of about 

 the same size as the latter, hemispherical or sometimes between 

 hemispherical and low conical, with a rather large orifice. This 

 is due to both forms. But in the above quoted not quite certain 

 specimen of f. sublævis from the Christiania Fjord they are nearly 

 conical, though. never acute. Also here only the greater part of 

 the roof falls away. Some small conceptacles in company with 

 the latter, about 200 [x in diameter or less, are probably those of 

 antheridia. I have not seen the carpospores, nor the spermatia. 



The colour of the plant is quoted by Areschoug 1. c. to 

 be „nunc purpureo-rubri nunc cretaceo-albidi", by Rosanoff „rose- 

 violacée", by Solms-Laubach „ hell- viol ett" and by Hauck 

 „rotlich-lila". Authentic specimens in Areschoug's herbarium from 

 the Bahusian coast of Sweden are lilac, almost fully according 

 with no. 48 in Saccardo, Chromotaxia. Helgolandian specimens 

 partly are light lilac partly and especially f. sublævis approaching 

 that of L. polymorphum, or with a more violaceous tinge and 

 more often nearly coinciding with that of L. lævigatum. British 

 specimens that I have seen most nearly accord with the darker 

 Helgolandian. A specimen from Cherbourg has a very light viola- 

 ceous shade. Specimens with us that I have gathered in Nordland 

 accord with Bahusian, partly, however, a little darker partly with 

 a yellowish-violaceous shade. At Berlevaag, the most northern 

 locality known, it sometimes is yellowish, here and there with a 

 very faint violaceous tinge, sometimes bluish violet. 



