Marine Plants of Nha Trang ■ — Dawson 
455 
Fig. 60. a, b, Polysiphonia fragilis: a. Part of a tetrasporangial branch near its apex showing the arrangement of 
the five pericentrals and a persistent trichoblast, X 108; a portion of a branch bearing four pericentrals showing 
an uncommon instance of transformation to five pericentrals, X 91. c, Polysiphonia suhtilissima: Mid-portion of 
a filament showing the sparse scar cells, one divided to initiate an exogenous branch, X 100. d, e, Polysiphonia 
tongatensis: d. An upper part of a plant showing trichoblasts, scar cells, and branches, X 65 ; a lower part of a 
plant, X 65. /, Polysiphonia sp.: Apical portion of an axis of 11329 showing irregular arrangement of scar cells, 
X 100. g, h, Polysiphonia coacta: g, Portion of a branch of 11310 near the tip, X 235; h, part of a branch of 11259 
from a short distance below the tip, X 90. 
