— 103 — 



the other may be signified otherwise. No cloubt Kützing had no 

 clear understanding of the fact that the specimens which he had 

 received from Binder was identical with his oven species Hormo- 

 ceras fruticulosum. 



Of Kylin's two forms of C. penicillatum (Kylin 1910, pag. 34) 

 no doubt forma fasciculata may be to refer to C. fruticulosum: 

 forma typica probably is another species x ). My three forms of C. 

 fruticulosum (Plate I, figs. 1, 4 and 5) (f. rescissa sent, mea, peni- 

 cillata and rubroides) no doubt form a connected whole being so 

 near related that there is no reason for dividing this species. The 

 forma penicillata may be regarded as the central form. Another 

 thing it is whether I am right in using the name "rescissa" for 

 my first form. Kylin seems (cp. cit. p. 35) to be of opinion that 

 his species C. rescissum has nothing to do with my f. rescissa. As 

 I cannot say with certainty whether I am right in this point I 

 prefer not to use the name "rescissa" for my form, giving this the 

 name dichotoma (Plate I, fig. 1). C. rescissum Kylin yet is closely 

 related to C. fruticulosum. 



The group of the Ceramium species with zones with growing 

 upper margins is in my opinion composed in the following manner: 

 C. Areschougii Kylin. 



C. sp.; syn: C. penicillatum f. typica Kylin. 

 C. rescissum Kylin. 

 C. fruticulosum Kütz. 



a. dichotoma syn. ex. p. C. fruticulosum f. rescissa H. E. P. 

 Plate I, fig. 1. 



ß. penicillata = Hormoceras fruticulosum Kütz. sensu strict, 

 et C. penicillatum Areschoug; syn: C. penicillatum f. fasci- 

 culata Kylin. Plate I, fig. 4. 

 y. rubroides. Plate I, fig. 5. 

 C. fruticulosum has no proteid-containing cells in the bark. 



On the development of main axes and secondary 

 shoots in C. diaphanum, fruticulosum and rubrum. 



In these three species we find both pure dichotomous forms and 

 such with development of main axes. The causes of these mor- 

 phological differences are truly still obscure; yet we seem to be 



1 ) I have seen original specimens of this form. 



