42 



CARL SKOTTSBERG, MARINE ALG.E 2. RHODOPHYCE^E. 



distinct. As a rule there are three, in older parts as many as five, layers, a central one of 

 very large cells (fig. 18 c), clearly visible also in surface view (fig. 18 d — e). In the 

 younger lamina (18 d), 2 to 4, in the older (18 e) as many as 10 cortical cells correspond 

 to one central cell. I ha ve not met with this structure in Nitophyllum, where the cortical 

 cells, in the lamina if not in the costa, are of the same size and shape as the central 

 cells from which they are cut off, while, in Hemineura, we find a structure approaching 

 that of Platyclinia. 



Platyclinia was described by Agardh in Sp. Alg. III: 3 p. 103 and brought to 

 Neuroglosseae; in anatomical characters, it shows a superficial likeness to Neuroglossum. 



aabodhosa 



FPöP^ 





Fig. 18. Platyclinia; a — C P. fuegiensis å minute proliferation, b older tip, C frond in section and d — e seen from sur- 

 face, cells of central lamella with dotted outlines; f P. Crozieri Herb. Agardh no. 31109, surface view. a — b x 360, 



C— f x 180. 



P. stipitata (Harv?) is the species mentioned first, but P. Crozieri should rather be re- 

 garded as the generic type (comp. Agardh 1. c. p. 107). The type specimen of P. stipitata 

 was collected by Miss Hussey on the coast of Australia and bears tetraspores. The f igure in 

 Anal. Algol. Cont. V, t. 3 f . 9 represents a cross section of this plant. Under the same name 

 lies another specimen, collected by Meredith in Tasmania (no. 31098), and this has ripe 

 cystocarps. It is no Platyclinia, but a monostromatic Nitophyllum (stipitatum Harv.?). 

 Regarding P. Crozieri, I have shown 1. c. p. 31 that Agardh identified Nitophyllu?n 

 Crozieri Hook. Fil. et Harv. from Cape Horn with a plant from Australia showing 

 Platyclinia-structure, that they are altogether different and that the former is a true 

 Nitophyllum in every respect. Indeed, the binomial Platyclinia Crozieri is absurd and 

 ought to disappear, because it arose from a wrong identification of two very distinct 



