HOW TO KNOW THE SEAWEEDS 



118b Thallus composed of parenchymatous cells, lightly calcified su- 

 perficially, or sometimes apparently uncalcified. Fig. 157. .Padina 



Fig. 157. Padina vickeisiae 

 Hoyt 



A portion of a plant show- 

 ing the irregularly split blade, 

 the imroUed margins, the con- 

 centric hair Unes and some 

 rows of sporangia, X 0.65. 

 This is a very lightly calcified 

 species found from North Caro- 

 Hna to Florida and Texas. P. 

 sanctae-crucis Borgesen, which 

 is strongly calcified on the un- 

 der side occurs in southern 

 Florida. 



Figure 1 57 



119a Thallus consisting of a simple stalk bearing a disc at the top. 

 Fig. 158 Acetabularia 



Fig. 158. Acetabularia crenulata Lamour- 

 oux 



Upper part of a plant, X 3. This is a 

 common and highly attractive green alga 

 on broken coral in quiet water in southern 

 Florida and west to Texas. Even a rusty 

 old coffee can may be found wonderfully 

 glamorized by these beautiful little um- 

 brella-like plants. Two or three other, less 

 conspicuous species may be encountered 

 in Florida. 



Figure 158 



120 



