| Gayliella recticortica (E.Y. Dawson) T.O. Cho & S.M. Boo, 2008 |
| Gayliella taylorii (E.Y. Dawson) T.O. Cho & S.M. Boo, 2008 |
| Gayliella transversalis (F.S. Collins & Herv.) T.O. Cho & Fredericq, 2008 |
| Hollenbergia E.M. Woll., 1972 |
| Hollenbergia nigricans (N.L. Gardner) E.M. Woll., 1972 |
| Hormoceras Kütz., 1841 |
| Hormoceras flaccidum Harv. ex Kütz., 1862 |
| Irtugovia L.P. Perestenko, 1994 |
| Irtugovia pacifica (Harv.) L.P. Perestenko, 1994 |
| Microcladia Grev., 1830 |
| Microcladia borealis Rupr., 1850 |
| Microcladia californica Farlow, 1875 |
| Microcladia coulteri Harv., 1853 |
| Platythamnion J. Agardh, 1892 |
| Platythamnion heteromorphum (J. Agardh) J. Agardh, 1892 |
| Platythamnion pectinatum Kylin, 1925 |
| Platythamnion pectinatum var. laxum W.R. Taylor, 1945 |
| Platythamnion reversum (Setch. & N.L. Gardner) Kylin, 1925 |
| Platythamnion tepocense E.Y. Dawson, 1944 |
| Platythamnion villosum Kylin, 1925 |