Cofliacese 



233 



verticillate branching also occurs in Tydemania expeditionis, in Boodleopsis 

 and in the capitulum of both species of Rhipocephalus (A. & E. S. Gepp, 11). 

 In addition to the main branches there are often more or less prominent 

 papillate outgrowths which may occur in great quantity, not infrequently 

 cohering to form a continuous cortex covering the external surface of the 

 thallus. This cortex may be uncalcified, as in Flabettaria petiolata, or 

 calcified, as in many species of Udotea, etc. In Cladocephalus there are 

 numerous ' pseudo-lateral ' branches forming an uncalcified labyrinthine 

 cortex (fig. 152 B and (7). There are also 'pseudo-conjugating' filaments in 



Fig. 152. Cladocephalus excentricus A. & E. S. Gepp. A, plant i nat. size ; B, section of the 

 outer portion of the thallus showing the pseudocortex, x 245 ; C, longitudinal section near 

 the apex showing the young branches of the cceiiocyte, x 200. (From Wille, after 

 A. & E. S. Gepp.) 



Rhipiliopsis, consisting of lateral outgrowths which meet but never coalesce. 

 In the Codiese the cortex consists of contiguous branch-endings, which in the 

 genus Pseudocodium are laterally coherent. 



There is usually a constriction at the base of each branch of a dichotomy, 

 and partial septa are often formed at these points due to the development of 

 a ring-like ingrowth of the cell-wall. In Callipsygma this ingrowth is a 



