English: Compsopogon oishii. Fig. 1: younger and older fronds in nat. state and size.--Fig. 2: a 28 cm. long filament detached, (thickness ca. 2/1); portion marked a, ca. 800 u thick; b, 500 u; c, 300 u.--Fig. 3: portion of fig. 2 marked d, magd. to show unequal thickness.--Fig. 4: portion of fig. 2 marked e, magd.--Fig. 5: cross-section of a branch 200 u thick, the central cell still present, 140/1.--Fig. 6: surface-view of a thick branch, 390/1.--Fig. 7: longitudinal section of a branch showing the central cell, 220/1.--Fig. 8: rooting portion of filament show in fig. 4 of PL- CXXXII, magd., 390/1.--Fig. 9: monospore (0.015-0.02 u), 600/1.--Fig.10: monospore just germinated, 600/1.--Fig. 11: young prothallium, 340/1.--Fig. 12: more advanced prothallium having 6 vertical branched, 220/1.--Fig. 13: vertical section of a prothallium on the lead of Valisneria, having two young fronds a and b, 220/1.