CHLOROPHYCE 171 
densely branched in all directions without possess- 
ing any main axis. It forms gelatinous cushions 
or irregularly globular masses. Bolbocoleon has a 
creeping thallus of rows of cells without erect 
branches, though the cells exhibit an upward pro- 
tuberance. Small conical cells, ending upwards in 
fine bristles, and with very little colouring matter, 
Fic. 53.—Rolbocoleon piliferum. a, filament with hairs; b, cells with 
zoospores. Highly magnified. (After Pringsheim.) 
occur on and between the ordinary vegetative cells. 
Entoderma grows as an endophyte within the mem- 
branes of other Alge ; it is irregularly branched, and 
sometimes is developed after numerous cell-divisions 
into a kind of tissue-mass. The divisions as a rule, 
however, take place only in the pointed terminal 
cell. Epicladia is a creeping epiphyte on the surface 
of Flustra and other Bryozoa, and in many respects 
