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latter, f. typica and transitions to f. flexuosa growing together. It 

 is not unlikely that this form in part constitutes a hybrid between 

 L. fruticulosum and L. tophiforme, but on the other hand, as 

 remarked p. 3, it appears nearly impossible in this extremely varying 

 group of species to decide whether hybrids in fact arise. The 

 figured specimen exhibits transition to typical f. flexuosa, however, 

 also closefy approaching certain forms of L. tophiforme, that a 

 limit is very difficult to draw, and I possess several sterile speci- 

 mens which I have not been able to identify with certaint}^, as 

 also L. tophiforme shows a tendency to develop itself in the same 

 direction. It is nearly always sterile, or some other specimen very 

 scantily provided with conceptacles of cystocarps and sporangia, 

 the latter in this as well as in typical specimens of f. flexuosa 

 sometimes approaching those of L. tophiforme. I, however, have 

 not succeeded in finding the sporangia in the named most extreme 

 form, and it may be that this form in fact represents a separate 

 species. 



The structure of the frond is described by Kjellman 1. c. I 

 here only want to remark, that the inner cells of the cup-shaped 

 layers in the branches or processes frequently appear to be about 

 10—12 fi long and 5 — 6 /->- thick. The named layers are more 

 or less regular, in part depending on older overgrown concept- 

 acles of sporangia. 



The reproductive organs of this species are also described by 

 Kjellman 1. c. The conceptacles of sporangia in f. typica, f. 

 fastigiatd, f. intermedia, f. glomerata and f. curvirostra resemble 

 each other. They are scattered especially in the processes or upper 

 part of the branches or occasionally somewhat crowded, very little 

 prominent, in part not distinctly marked, and the slight^ convex 

 roof frequently about 250 — 300 p. in diameter, more seldom only 

 about 200 p. The roof is rather thick, and the muciferous canals 

 appear to be visible from the surface first in a rather late stage 

 of development of the conceptacles. In some specimens I partly 

 found the central or greater portion of the roof thinly decorticated, 

 and the canals visible and distinct in a number of about 30 — 10, 

 partly not decorticated and the canals not visible. However, in 



