261 
dually overgrown, as far as hitherto seen”. It may happen that the emptied con- 
ceptacles are filled with filaments growing out from the bottom of the conceptacle, 
but it also not unfrequently occurs that they are overgrown without being filled, 
and empty conceptacles are thus found at various depths in the thicker crusts. 
This was observed with all kinds of conceptacles. 
As mentioned above, I found in one locality (TL, north-west of N. Ronners 
Rev, 4—5,5 m, Sept. 1894, n° 5341) some specimens somewhat different from the 
Fig. 182. Fig. 183. 
Lithophyllum orbiculatum Supposed antheridial Lithophyllum orbiculatum. Cystocarpic conceptacles, À, show- 
conceptacles. In A small bodies are seen which are ing the pore and the carpogonia. 350:1. B, excentric section 
probably spermatia. 350:1. showing the inner crown and two carpospores at the peri- 
phery of the disc. 200:1. 
ones just mentioned. They form much more expanded crusts, up to 10cm or more 
in diameter, and the cells of the perithallium are thicker, 9—12 broad, 7—16(25) x 
long. These measurements, however, are only little different from those given by 
FosLie, who has also determined these specimens as Lith. orbiculatum forma. The 
hypothallium consists, as in the other specimens, of a single cell layer, but the cells 
are frequently elongated obliquely upwards, in the same direction as the perithallic 
filaments, and they are similar to the cells of these filaments (fig. 180 E, F). The 
examined crust contained sporangial conceptacles 77—122,y in diameter, with a 
single pore; in an old conceptacle a few not exhausted two-parted sporangia were 
still present. It must be left to further investigations to delermine whether these 
specimens really belong to L. orbiculatum. 
