Fig. 
PLATE VIII. 
Figs. 1-3.—Heteroplon pluma. 
g. 1.—Natural size. 
. 2.—Portion of hydrocladium, magnified ; front view. 
3.—Portion of stem with hydrocladia ; lateral view. 
Figs. 4-7.—Diplocheilus mirabilis. 
ig. 4.—Natural size. 
5.—Portion of stem with two hydrocladia, magnified ; showing front and back views 
of hydrothecee. 
Fig. 6.—Internode of a hydrocladium with its hydrotheca ; half profile. 
7.—Portion of hydrocladium consisting of two internodes, each with its hydrotheca ; 
half profile. 
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