260 SEAWEEDS 
plants, thus juxtaposed, each independent of the 
others, though inclosed within a common envelope, 
and not trichome-formations as in the Nostocaece. 
The filaments so formed by the colony ramify within 
shells often in company with Gomontia and Iastigo- 
Fic. 88.—Hyella carspitosa. a, young thallus, one of the branches divided 
into numerous cells; b, sporangia highly magnified. (After Bornet and 
Flahault.) 
coleus, and effect the disintegration of the shell sub- 
stance. Propagation is effected by the liberation of 
vegetative cells from the envelope (not in hormogo- 
nia), and by spores formed in sporangia by successive 
divisions of the protoplasm. Dermocarpa occurs as 
an epiphyte on other Alge, and consists of clusters 
