218 



thai the sporangia in such cases were not quite ripe, and would later on have been 

 divided into four spores, but as in other cases the divisions have shown to be al- 

 most simultaneous (fig. 134 C) it 

 seems most probable that disporic 

 sporangia occur besides tetrasporic 

 ones, as in several other species. 

 Sporangia with 4 spores found in 

 the Limfjord and in the Kattegat were 

 100—112/^ long, 34—48// broad; in 

 specimens collected in Bramsnses Vig 

 (Ise Fjord) they were only 53 — 91 p. 

 long, 14 — 25 fx broad. 



Antheridial conceptacles were 

 found in specimens from Staffans 

 Pig Flak in the Sound and from Brams- 



Lithothamnion Lenormamli. A, vertical section of crust with nses Fjord. In botll CaseS they Were 

 sporangia! conceptacles. iJ, tetrasporangium in two consecutive .jaa oca • ]• ii u 



sections. C, tetrasporangium in three consecutive sections. 350// in diameter, tllUS mUCh 



.163:1 B -200:1. larger than slated by Foslie (150 



—200 fj). In the specimens from the first named locality collected in September 

 they were fully developed and showed a rather complicated structure, the spermatia 

 being produced on the ultimate ramifications of dendroid systems of filaments given 

 off from several points of the inner surface of the conceptacle, from the bottom 

 and from the upper side as well (Plate III fig. 2). The structure of the antheridial 

 conceptacles is thus rather similar to those of Lith. polymorphum described by 

 Heydrich (Lith. Helg. p. 65, Taf. II fig. 1 — 3). The dimensions of the spermatia 

 seem to be 3 x 4 ij. 



The cystocarpic concep- 

 tacles are hemispheric to coni- 

 cal, 320—350 fi in diameter. 

 It is remarkable that the car- 

 pospores are not only produ- 

 ced at the periphery of the bot- 

 tom of the conceptacle but from 

 the whole face of the floor, a fact 

 by which our species differs, as 

 it appears, from the type not 

 only of the genus but also of the 

 family. The carpospores are 

 50— 63/z long, 21-32/i broad \ 



' Heydrich has in 1911 (1. c.) 

 established a new genus, Squamolithon, 

 founded on Lithotliamnion Lenormandi, 



Fig. 135. 



Litliothamnion Lenormandi. Vertical section of cystocarpic 

 conceptacle. 200:1, 



