96 Blackman and Tansley. 
or of both. Zygote germinates without resting. All the genera are 
endophytic. 
[The members of this very natural family all dwell in the intercellular 
spaces of either water plants or plants growing in moist places, and they 
all persist through the winter as akinetes and not as zygotes.] 
Genera. 
1. Chlorochytrium. Cohn, 1874. 
Cells oval or irregularly rounded. Chromatophore 
a parietal layer round the whole cell, containing many 
pyrenoids. Zoospores and gametes occur. Conjuga¬ 
tion of the latter takes place within the extruded 
mucilaginous inner layer of the gametangium. 
2. Stomatochytriunu Cunningham, 1888. 
Chiefly distinguished from Chlorochytrium by the 
absence of the mucilaginous investment of the 
gametes. 
3. Chlorocystis. Reinhard, 1885. 
Distinguished from Stomatochytrium by the chromato¬ 
phore only lining part of the cell and having only 
one pyrenoid. Maiine. 
4. Endosphaera. Klebs, 1881. 
Cell-shape and chromatophore as in Chlorochytrium. 
Gametes occur but not zoospores. 
5. Scotinosphaera. Klebs, 1881. 
Cell-shape and chromatophore as in Chlorochytrium. 
Reproduction by zoospores alone observed. 
6. Centrosphaera. Borzi, 1883. 
Cells oval, occurring in the mucilaginous sheaths of 
blue-green algae. Zoospores only known. 
7. Phyllobium. Klebs, 1881. 
Plant-body probably coenocytic and forming a branched 
tube deep within the stems of water-plants. Chloro- 
plast a thin parietal layer. Reproduction by 
zoospores and by anisogametes. A resting winter 
akinete is cut off in one part of the branched tube. 
(to be continued). 
R. Mud ley, Printer, Whitfield Street, W, 
