Fig. 
PLATE I. 
Figs.. 1-4.—Plumularia flabellum. 
1.—Natural size. 
g. 2.—Portion of a hydrocladium magnified ; lateral view. 
Fig. 3.—Same ; front view. 
Fig. 4.—Portion of branch, with origin of hydrocladia. 
Fig 
S 
Figs. 5, 6.—Plumularia laa. 
e. 5.—Natural size. 
. 6.—Portion of hydrocladium giving origin to a secondary bydrotheca-bearing ramu- 
lus ; magnified. 
Figs. 7, 8.—Plumularia dolochotheca. 
7.—Natural size. 
8.—Portion of hydrocladium ; magnified. 
