160 



SEAWEEDS 



y 



a 



d 



FIG. 47. Dictyogpha-ria favulosa. a, b, <, young specimens ; d, diagram of 

 cells joined by haptera ; e, haptera in side and surface views ; /, D. sericea, 

 surface view of frond ; g, bordering cells with haptera ; h, internal projections 

 from cell-walls of D. favulosa. Variously magnified. (Ex. Phyc. Mem). 



branched type, which leads on to forms with a higher 

 differentiation of thallus. In Apjohnia there is a 

 main stalk with numerous rugose constrictions and 



