348 
THE SEAWEEDS 
Fig. 173 . — Ballia Robertiana: a, plant; b, two 
pairs of opposite, alternately 
unequal, plumules; c, pinna from 
one of the major plumules; d, an 
involucre containing a favella; e, 
favella removed; f, spores. (After 
Harvey.) 
