Fig. 140 Lomentaria clavellosa. A-C, development of carpogonial 

 branch ( x 660). amc = accessory mother cell, 5c= support cell. D, 

 young cystocarp (X312). ac= accessory cell, i>c= support cells, 

 ^on = gonimoblast. E, mature cystocarp ( xpo). F, L. rosea^ life 

 cycle. G, H, L. clavellosa, antheridia ( x 660). I, L. clavellosa^ 

 plant (xf). (A-C, F-H, after Svedelius; D, E, after KyUn; I, 



original.) 



LOMENTARIACEAE : Lometitaria (pod with constricted joints). Fig. 

 140 

 The filamentous fronds are hollow when mature, with or without 

 constrictions at the nodes but without diaphragms. Branching is 

 irregular or unilateral. The hollow central region originates from a 

 branching structure which later on separates in order to form the 

 outer cell layers, although a few longitudinal filaments of the 

 original multiaxial structure are left in the centre. These may be 

 branched and joined to each other by secondary pit connexions. 

 The plant, which is enclosed in a thick gelatinous cuticle, may bear 

 unicellular hairs that have arisen from the epidermal layer. The 

 adult thallus has developed from a group of eight to twelve apical 

 cells, each of which produces a longitudinal filament, whilst the 



247 



