HOW TO KNOW THE SEAWEEDS 



157a Tetrasporangia borne individually in the cortical tissue of the 

 blade, not touching each other or occurring in masses. Fig. 198. . 

 158 





Fig. 198. Cryptonemia obovata J. Agardh 



Part of a transection of a tetrasporic 

 blade showing an individual tetrasporon- 

 gium in the cortex, X 520. One of the 

 characteristic medullary filaments with 

 highly refractive contents is shown in 

 cross section. 



Figure 198 



157b Tetrasporangia borne in masses embedded deeply in the blade. 

 Fig. 199 159 



Fig. 199. Iridophycus sp. 



Part of a transection of a young tetra- 

 sporic blade to show the origin of the 

 sporangia (undivided) among the medul- 

 lary filaments well inside of the cortex 

 (Modified after Kylin). 



^^'^^(J 



4B ^ Ag^ "^ 



cPO ^ 



O Q^ 



p^^:g 



Figure 199 



158a Cortex composed of small cells arranged more or less clearly in 

 anticlinal rows; medulla without refractive filaments. Fig. 200. . . 



Grateloupia (in part) 



Fig. 200. Grateloupia maxi- 

 ma (Gardner) KyUn 



Transection of a blade 

 through a cystocarp show- 

 ing cortical cell rows, espe- 

 cially on lower surface. X 

 200. 



This is one of the broad 

 species with entire blades 

 which may be found along 

 the Cahfornia coast. Non- 

 prohferous sp6cimens of G. 

 schizophylla key out here (see Fig. 194). Such broad, membranous 

 species of Grateloupia do not occur along the Atlantic Coast 



Figure 200 



152 



