268 



The cystocarpic conceptacles have the same shape and size as the sporangial 

 ones. The papillae lining the ostiole were found more developed than in the spor- 

 angial conceptacles. The structure of the cystocarp rather resembles that of Corallina, 



a large disc-shaped cell occupying 

 the bottom of the conceptacle 

 giving off at the periphery seriate 

 carpospores and covered with 

 numerous closely placed oblong 

 cells filled with protoplasmatic 

 contents, the morphological char- 

 acter of which could mot be de- 

 termined, as trichogynes were 

 in no cases observed (fig. 190). 

 The cystocarpic conceptacles 

 become overgrown and sunk in 

 the crust as also the sporangial 

 conceptacles. 



The structure of the frond, being polystromatic to Ihe margin, and the sHghtly 

 prominent conceptacles being sometimes overgrown and deeply sunk in the frond, 

 are the principal characters distinguishing this species from the foregoing, with 

 which it agrees in its disporic, though smaller sporangia. It is apparently not 

 identical with Melobesia Coiallince Solms (Corall. p. 9, Taf. II, fig. 25, III fig. 21—24) 

 which differs, to judge from the figures, by tetrasporic sporangia, occupying the 

 central part of the conceptacle, by the want of columella, and apparently by the 

 structure of the frond, the basal cell-layer being very low. 



Found with sporangia and cystocarps in July and August. 



Localities. Sk: YT, YU, Hanstholm, 2— 6 meters; Hirshals, on the mole. 



4. Lithophyllum pustulatum 



(Lamour.) Foslie forma"! 



Mention may be made here of an alga 

 recorded once growing on Corallina offici- 

 nalis but which could not be identified 

 with certainty on account of the incomplete 

 state of the present material. It forms thin 

 red crusts, the peripheral part of which is 

 monostromatic with cortical cells, only 

 14 — 20 /A thick, while the central portion, 

 consisting of 2—3 cell-layers, besides the 

 cortical cells, has a thickness of up to 80 



Fig. 190. 



Lithophyllum Corallina-. Vertical section of cystocarpic conceptacle. 



350: 1. 



Fig. 191. 



[Jthophylluni pusiiilatuin forma?. Vertical section of 

 one half of an empty conceptacle. 205:1. 



