HOW TO KNOW THE SEAWEEDS 



89a Wall of tubular thallus only 1 cell thick (Fig. 124); color greenish. 

 Fig. 125 EnteromoTpha 



Fig. 124. Enteromorpha sp. 



A transection of an axis to show the 

 single layer of cells and the hollow struc- 

 ture. 



Figure 124 



Fig. 125. Enteromorpha 

 spp. 



A. Enteromorpha tubu- 

 losa (Kiitzing) Kiitzing. A 

 portion of an unbranched, 

 hairlike filament, X 7. 

 B. Enteromorpha clathrata 

 (Roth) Greville. A small 

 part of an axis with sev- 

 eral uniseriate branchlets, 

 X 80. This genus con- 

 tains some of the most 

 widespread and cosmo- 

 politan of the marine al- 

 gae. Many species may 

 be found on either coast, 

 and in a great diversity 

 of habitats. Most of them 

 are exceedingly variable 

 in form and some are no- 

 toriously difficult to iden- 

 tify. E. hnza (Linnaeus) J. 



Agardh is a species which is flattened in upper parts like Ulva, but 



hollow at the base like Enteromorpha. 



Figure 125 



89b Wall of tubular thallus more than 1 cell thick; color brownish or 

 reddish 90 



95 



