415 



C. fasciculata (pseudo-ramified filaments with intercalary heterocysts) as 

 separate species; for although the extreme points of the scale of forms 

 of this species may seem to have their characters well defined, in 

 reality they are evenly allied to each other through intermediate forms. 

 Thus one may find unramified filaments with only hasal heterocysts 

 but also with a few or even many intercalary ones, and in ramified 

 filaments the number of intercalary heterocyts will vary from 0 to 

 many. Hence in many cases one should be obliged to refer a cer- 

 tain form to either the one or the other of the two Bornet & Fla- 

 hault's species even though it does not quite agree with either the 

 special characters of the first one or of the second of those two species. 

 Because of the beforesaid I have preferred to unite C. scopulorum 

 and C. fasciculata into one species: C. scopulorum (Weber & Mohr) 

 A g ard h emend, containing all continous forms of the two „species" 

 and limited by the species -description above 1 ). We may distinguish 

 between the following though rather often badly characterized forms: 

 f. simplex with unramified, f. subsimplex with slightly, and f. ramosa 

 with greatly ramified filaments. It must be said, that those bunches 

 or bundles of „branches" often found on „C. fasciculata" are not al- 

 ways due to ramifications of the filament on wich they are placed, but 

 often to the development of hormogonies, which have placed themselves 

 there and have grown into piliferous bundles of filaments. 



113. Gloiotrichia natans fHedw.) Rabenhorst. 

 Deutschlands Kryptogamen-Flora, p. 90, 1847. 

 var. a, genuina. 



Sporis in parte inferiori latioribus qvam in parte superiori. 

 var. ß, aeqvalis Nob. 



Sporis longissimis, cylindricis, per totam longitudinem aeqvi- 

 crassis. 



114. Mastigocoleus testarum Lagerheim. 



Note sur le M., nouveau genre des Algues marines de l'ordre 

 des Phycochromacées, Notarisia, 1, p. 65, 1886. 

 var. a, genuina. 



Thallo immerso glauco vel pallide aerugïneo. Trichomatibus 

 eodem colore. Articulis saepius cylindricis vel subcylindricis. 



var. ß, rosea Nob. 



Thallo immerso roseo vel 1 i 1 a c e o , maculas orbiculares 

 demum confluentes efficiente. Trichomatibus purpureo - roseis vel 

 purpureo-violaceis. Articulis saepe irregulariter inflatis. 



*) Perhaps Calothrix Crustacea Thuret, which I know only from 

 Bornet & Flahault's descriptions, belongs to the widened C. scopu- 

 lorum. But future examinations must settle this point. 



