HOW TO KNOW THE SEAWEEDS 



116b Segments not particularly short; intergenicular medulla multizonal. 

 Fig. 154 Amphiroa 



Figure 154 



Fig. 154. Amphiroa iragilissima (Linnaeus) Lamouroux 



A portion of a loosely branched plant showing the elongated in- 

 tergenicula separated by conspicuous genicula, X 3. This is the most 

 widespread of our species, occurring from North Carolina to Florida. 

 At least two other species, one of them quite strongly flattened, may 

 be found in Florida. A. zonata Yendo is frequent in southern Cali- 

 fornia. 



1 17a Thallus fan-shaped 118 



1 17b Thallus not fan-shaped 119 



118 



