90 



which are imperceptible to the naked eye, 150 — 250 >j- in diameter. 

 These points are slightly lighter than the surrounding parts, in the 

 middle intersected with a single and rather indistinct canal, and 

 the periphery forming a more or less light and very narrow annular 

 border, not, however, raised above the surface of the frond. By 

 and by the roof becomes sltghtly convex, seldom nearly hemisphe- 

 rical or depressed-conical, rather thick, but in all very little pro- 

 minent, of the same diameter as above quoted, with the orifice 

 more distinct, but, so far as I have seen, not yet any spores for- 

 med. Later the central portion of the roof gets thinly decorticated, 

 but the conceptacles apparently not yet fully developed, nor did I 

 find any distinct spores in the, however, very few conceptacles 

 that I have seen in this state of development. 



In the specimens from Helgoland I found some few concep- 

 tacles very nearly resembling the named convex ones, and in others 

 a smaller or greater part of the central portion decorticated, seen 

 from the surface apparently by and by assuming a cup-shaped or 

 depressed-oblong form, with not or very slightly elevated edges, 

 successively depressed towards the centre, and the not much de- 

 pressed central portion traversed by a single canal. Conceptacles 

 in the last named state were numerous and appeared to be fully 

 developed, at least some of them containing apparently mature 

 spermatia, and others not unlikely carpospores, the former flattened 

 and rounded or rounded-angulate, about 60 //. in diameter, the 

 latter broadly cuneate or oblong, but in all rather irregular, about 

 70 /a long and 40 — 50 //. broad. At maturity the orifice becomes 

 larger, a smaller or greater part of the roof gets dissolved, or the 

 whole roof falls away, leaving a rather deep hole. 



From the rather scanty materials at my disposal, with the 

 conceptacles in the specimens from Mandal in one and the same 

 state of development, and so also in those from Helgoland, I have 

 not been able to decide with certainty whether the first named 

 really bear cystocarpic conceptacles in development, or both these 

 and the antheridian ones. And I am not sure whether the last 

 named specimens only were provided with spermatia, and if so, 

 the latter are extremely varying, or if in fact are both the named 



