| Stylochus tripartitus Hyman, 1953 | Aug, 1936 |  |  | on kelp rhizoids, one specimen taken alive. | 
| Stylochoplana gracilis Heath & McGregor, 1912 | prior to 1953 |  | kelp | collected by McGregor and Yonge. | 
| Notoplana saxicola (Heath & McGregor, 1913) | Aug, 1936 |  |  | collected by Hyman on kelp rhizoids. | 
| Notoplana acticola (Boone, 1929) | prior to 1953 |  |  |  | 
| Notoplana sciophila (Boone, 1929) | prior to 1953 |  |  | stated by Boone to occur in the vicinity of Pacific Grove. | 
| Eurylepta aurantiaca Heath & McGregor, 1912 | prior to 1912 |  |  | collected by Heath. | 
| Trigonostomum tori Willems, Artois, Vermin, & Schockaert, 2004 | pre 1986 |  |  | Karling (coll. SMNH) | 
| Eurylepta species (3) Morris, Abbott & Haderlie, 1980 | 1980 or earlier |  |  | from exposed, deeply shaded, surfaces of seaweed.  Low intertidal zone. | 
| Polycystis ali form California Karling, 1986 | Mar-Apr 1969 |  |  | tide pools and shallow water, shell gravel, stones and algae in several places. | 
| Gyratrix hermaphroditus Ehrenberg, 1831 | Mar-Apr 1969 |  | sand, pebbles | several places in the tidal zone and in tidepools, sand, pebbles and algae. | 
| Gyratrix hermaphroditus Ehrenberg, 1831 | Sep 1960 |  | sand, pebbles | several places in the tidal zone and in tidepools, sand, pebbles and algae. | 
| Leptoplana littoralis Morgan, 1905 | 1905 or earlier |  |  | Pacific Grove, California. | 
| Proschizorhynchella lingulata Karling, 1989 | Sep 1960 |  | sand | under wrack on a sandy beach. | 
| Promesostoma dipterostylum Karling, 1967 | Sep 15, 1960 |  | seaweed and stones | Great Tidepool, washed out from seaweed and stones. |