216 



Fig. 166. Dictyopteris delicatula Lamx. 

 A part of the thallus. (About 3:1). 



which pores are present (Fig. 167 b) 



produces figures drawn by Bornet 



lose; it is coloured blue by chlor-zino-iodine 



section the cells of the 



strings are found to be 



long , cylindrical with 



oblique end-walls. 



The hairs are only 

 present upon the one side 

 of the thallus ; they are 

 placed many together in 

 roundish or oval groups 

 and occur regularly upon 

 both sides of the mid-rib. 



In the basal part the 

 plant is fastened to the 

 substratum by means of 

 rhizoids. These grow out 

 partly from the cells along 

 the margin of the thallus 



Dictyopteris Lamx. 



1. T). delicatula Lamx. 



Lamouroux in Journ. Phi- 

 lorn., 1809, no.20, tab.6, fig.B. 

 A. VicKERS, Phycologia Bar- 

 badensis, part II, pi. III. 



Haliseris delicatula C. Ag., 

 Species, p. 144. J. Agardh, 

 Spec. Alg., vol. I, p. 116. KuT- 

 ziNG, Tabulae Phycologicse, 

 vol. IX, pi. 56, fig. II. 



The thallus consists of 

 two layers of cells (Fig. 

 167 a) with the exception 

 of the ribs in the edges 

 and in middle of the frond 

 where it is composed of 

 several layers of cells. In 

 transverse sections these 

 ribs are seen to contain a 

 string composed of cells 

 with very thick walls in 

 Of these M"^ Vickees re- 

 The wall consists of cellu- 

 In a longitudinal 



Fig. 167. Dictyopteris delicatula Lamx. 



rt, transverse section of the thallus with a 



group of hair, b, transverse section of the 



edge of the thallus. 



