106 



In the above quoted specimen of f. laxa I found only two 

 conceptacles in the crust, which are probably not fully developed, 

 hardly perceptibly raised above the surface of the frond and much 

 flattened, and of about the same diameter as in the preceding form. 

 Some sporangia found in overgrown conceptacles were about 180 

 jj. long and 60 — 90 /j. broad. 



In f. rosea the named conceptacles are frequently rather den- 

 sely crowded in the crust and knobs, the roofs occasionally con- 

 fluent or nearly confluent, also here about 300 — 350 fi in diameter, 

 and partly much partly less flattened. In a British specimen kindly 

 sent me by Mr. Batters I found them not or scarcely raised above 

 the surface of the frond, indistinct and much flattened, but they were 

 probably not fully developed, although the sporangia appeared to be 

 mature. In another British specimen from the same locality they fully 

 accord with those in Norwegian specimens, distinctly marked, slightly 

 prominent and more or less flattened. In the above quoted Ame- 

 rican specimen of this form (pl. 17, flg. 14) the conceptacles are 

 of the same size, but much flattened and in part nearly disc-shaped, 

 though very little prominent. The sporangia are of about the same 

 size as in f. densa, or a little smaller. Cp. Batt. 1. c. 



The above named conceptacles finally grow down into the 

 frond. Overgrown ones sometimes are numerous sometimes very 

 few in number, or apparently even wanting, which not unlikely 

 may be connected with the fact, that the cystocarpic and antheri- 

 dian conceptacles appear not to occur in the same individuals as 

 those bearing sporangia. However, sometimes the whole roof falls 

 away and leaves a rather shallow scar, and now and then I found 

 such scars covered with a new, local formation of tissue ; the con- 

 ceptacles being densely crowded this new formation even stretched 

 over more ones. 



Cystocarpic conceptacles have with certainty only been found 

 in f. densa. They are scattered or crowded over the crust or 

 knobs without any order, conical, about 500 — 600 /j. in diameter 

 at the base, with a single oriflce, and a little above the middle or 

 towards the apex nearly always more or less constricted, the upper 

 portion partly acute partly rather blunt. This portion or a part 



