207 



larly alternating with the series of hairs (Fig. 157) ; they are 

 placed most often nearest the lower row of hairs. The rows of 



oOQogppo 



Fig. 160. Padina variegata (Lamx.) Hauck . 

 a, 'transverse section of the thallus with groups of hairs, b, transverse sec- 

 tion of the thallus with rhizoids near the base, c, epidermal cells from the 

 lower fase of the thallus. (About 9U : 1). 



tetrasporangia are not always uniform but often separate in dis- 

 persed smaller groups of sori. As mentioned above these are 



Fig. 161. Padina variegata (Lamx.) Hauck. 



a, transverse section of the antherial zone with indusium. b, antheridia. 



c, antheridia seen from above, [a, about 50 : 1 ; b, c, about 170: 1). 



covered by a well-marked indusium (Fig. 159 a, c). The shape of 

 the tetrasporangium is roundish pear-shaped. 



14* 



