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The segments of Corona superior (Fig.6B) have a somewhat 
irregular form, oblong cordate, often somewhat emarginated on 
the side turned outward and bear 2—3 hair-scars. In some spe- 
cimens we generally find two scars, seldom three, in others three 
and only seldom two. They may be found one behind the other 
or quite irregularly. The shape of the Corona superior therefore agrees 
well with the figure of Solms and the same may be said of that 
of the Corona inferior (Fig. 6 C); the segments are here almost rectan- 
gular, but somewhat laced in the middle. The breadth of the dise 
is about 3—5 mm. 
The gametangia are spherical and occur in a number of about 
80 in each ray. They are about 160 broad. A very large 
number of gametes are developed in them. Contrary to what is 
the case in Acetabularia mediterranea where the gametangia get 
free and only after a resting period, often lasting several months, 
develop the gametes, these here come to existence while the game- 
tangia are still enclosed in the rays. The gametangia are opened 
by means of a similar cover as in A. mediterranea. At the same 
time as the gametangia are opened, large holes are formed in each 
corner of the rays most probably by decomposition of the walls, 
through which holes the gametes can escape. It seems that these 
holes arise simultaneously in all the gametangia of the disc, at all 
events it has been the case in all the discs I have seen in this 
stage of development. The gametes are ovate and have most 
probably two cilia which I have not seen, though the gametes were to 
be found here and there in the emptied gametangia or in the rays; 
I have seen them lying in couples or more or less joined together, 
also some larger roundish bodies were found most likely zygotes 
and longer cylindrical cells: young plants. 
Yet I may add that the plant does not seem to have any 
fixed growing or resting period; at any rate plants collected in the 
months of January and February were found in all different stages 
of development. I have found quite young plants without disc 
but with two or three whorls of hairs in accordance with Harvey’s 
figure 2 PI. XLII (Nereis Bor.-Am.) of Acet. crenulata; plants were 
found on which the disc was as yet quite small and had a whorl 
of hairs in the corona superior; individuals were found on which 
this whorl of hairs had fallen off but where the formation of the 
gametangia had not yet begun and so on, until also individuals 
with emptied gametangia were found. Now the disc and stalk die 
