242 



RHODOPHYCEAE 



of Lomentaria rosea (cf. below) in European waters where the 

 gametophytic generation has been secondarily suppressed. The 

 monospores have been interpreted as morphologically equivalent 

 to either the carpospores or the tetraspores, the latter interpretation 

 being the one adopted in this volume. 



RHOD YMENIALES 



*Rhodymeniaceae: Lomentaria (pod with constricted joints). Fig. 

 162. 



The filamentous fronds are hollow with constrictions at the 

 nodes, whilst branching is irregular or unilateral. The hollow 

 central region originates from a branching structure which later on 



Fig. 162. Lomentaria clavellosa. A-C, development of carpogonial branch 

 (x66o). amc = accessory mother cell, ^c = support cell. D, young cystocarp 

 (X312). ac = accessory cell, 6c = support cell, ^on = gonimoblast. E, mature 

 cystocarp ( x 90). F, L. rosea, life cycle. G, H, L. clavellosa, antheridia ( x 660). 

 I, L. clavellosa, plant ( x f ). (A-C, F-H, after Svedelius; D, E, after Kylin; 

 I, original.) 



