132 SEAWEEDS 
The Geographical Distribution is general, and the 
best-known British marine forms are V. dichotoma, 
V. synandra, V. Thureti, V. spherospora, end V. 
litorea, — 
CoDIACE. 
General Characters—The order is represented by 
the genera Codium and Bryopsis, differing in habit and 
mode of branching, but agreeing in the production 
Fic. 35.—Codium tomentosum. a, part of section showing club-shaped cells 
of periphery with lateral sporangia highly magnified ; 6, one such cell with 
sporangium more highly magnified. 
of gametes of two sorts, between which conjugation, 
though it has not been observed, may yet be pre- 
sumed with much probability to occur. Derbesia, also 
included here, is of more simple vegetative develop- 
ment, and possesses, so far as is known, but one kind 
