| Freemania litoricola (Heath & McGregor, 1913) | prior to 1912 | | | under stones below medium tide-mark along southern shore of Monteray Bay |
| Pseudalloioplana californica (Heath & McGregor, 1913) | prior to 1913 | | | |
| Planocera burchami Heath & McGregor, 1912 | prior to 1912 | 18 m | | 5 individuals. |
| Licheniplana lepida Heath & McGregor, 1912 | prior to 1912 | | | four individuals collected on the under surface of stones on the southern shore of Monterey Bay, |
| Eurylepta aurantiaca Heath & McGregor, 1912 | 1912 or earlier | | | fairly common in Monterey Bay and the neighboring coast where it occurs under stones or crawling along the bottom in comparitively shallow water. |
| Euryleptodes pannulus Heath & McGregor, 1912 | 1912 or earlier | | | one specimen. |
| Graffizoon lobatum Heath, 1928 | prior to 1845 | | | in plankton |
| Stylochus californicus Hyman, 1953 | prior to 1953 | | | |
| Leptoplana chloranota (Boone, 1929) | prior to 1929 | littoral | stones | under stones |
| Notoplana rupicola (Heath & McGregor, 1913) | prior to 1912 | | | |
| Notoplana saxicola (Heath & McGregor, 1913) | prior to 1912 | intertidal | | taken on masses of algae in tide pools. |
| Notoplana inquieta (Heath & McGregor, 1913) | prior to 1912 | | | |
| Notoplana acticola (Boone, 1929) | prior to 1929 | | | |
| Copidoplana tripyla Hyman, 1953 | prior to 1953 | | | found in the Fisher collection, labeled L. acticola Monterey". |
| Alloioplana californica (Heath & McGregor 1913) | prior to 1912 | | | taken by the original describers at Monterey Bay and 'to the south for at least 34 miles'. |
| Alloioplana californica (Heath & McGregor 1913) | prior to 1939 | | | reported by Ricketts as relatively abundant near Monterey under large boulders. |
| Pseudostylochus burchami Heath & McGregor, 1913 | prior to 1912 | 20 m | | |
| Pseudostylochus burchami Heath & McGregor, 1913 | Apr 12, 1931 | 20 m | | collected by the MacGinities. |
| Pseudoceros luteus (Plehn, 1898) | prior to 1898 | | | |
| Planocera californica Heath & McGregor, 1913 | 1912 or earlier | | | southern coast of Monteray Bay, usually above mean tide in crevices of the rocks and beneath boulders on the beach. |
| Planocera burchami Heath & McGregor, 1912 | 1912 or earlier | 18.3 m | | five individuals. |
| Stylochoplana gracilis Heath & McGregor, 1912 | 1912 or earlier | | | eight individuals, all of which were taken on the broad thalli of Macrocystis pyrifera, growing in the vicinity of the wharf of the Del Monte Hotel, near Monterey. |
| Leptoplana rupicola Heath & McGregor, 1912 | 1912 or earlier | | | three individuals found adhering to the under surface of large rocks near extreme low-tide mark a short distance south of the entrance of Monterey Bay. |
| Leptoplana timida Heath & McGregor, 1912 | 1912 or earlier | | | rare as it is represented by only two individuals taken along the southern shore of Monterey Bay. |
| Leptoplana saxicola Heath & McGregor, 1912 | 1912 or earlier | | | small flatworm, numerous individuals taken at a point a few miles south of the entrance to Monterey Bay, |
| Leptoplana inquieta Heath & McGregor, 1912 | 1912 or earlier | | | four specimens, captured about the low-tide limit among the rocks, and in one case among the rhizoids of Macrocystis in Monterey Bay, |
| Phylloplana litoricola Heath & McGregor, 1912 | 1912 or earlier | | | nine individuals, living on the under surface of stones below the medium-tide mark along the sourthern shore of Monterey Bay, |
| Licheniplana lepida Heath & McGregor, 1912 | 1912 or earlier | | | four individuals collected on the under surface of stones on the southern shore of Monterey Bay, |
| Stylostomum lentum Heath & McGregor, 1912 | 1912 or earlier | | | six individuals taken near Monterey, at low-tide. |
| Aceros langi Heath & McGregor, 1912 | 1912 or earlier | | | single specimen taken on the southern shore of Monterey Bay. |
| Anciliplana graffi Heath & McGregor, 1912 | 1912 or earlier | | | several specimens of this species were collected in Monterey Bay and along the adjoining coast. |
| Euryleptodes cavicola Heath & McGregor, 1912 | 1912 or earlier | | | nine specimens taken at various points along the shores of Monterey Bay. |
| Euryleptodes phyllulus Heath & McGregor, 1912 | 1912 or earlier | | | several specimens taken on the shore of Monterey Bay. |
| Planocera californica Heath & McGregor, 1913 | 1912 or earlier | | | fairly abundant along the southern coast of Monterey Bay, and to the south for at least thirty-four miles. |
| Stylochoplana gracilis Heath & McGregor, 1912 | 1912 or earlier | | | eight individuals, all of which were taken on the broad thalli of Macrocystis pyrifera, growing in the vicinity of the wharf of the Del Monte Hotel, near Monterey. |
| Leptoplana rupicola Heath & McGregor, 1912 | 1912 or earlier | | | three individuals found adhering to the under surface of large rocks near extreme low-tide mark a short distance south of the entrance of Monterey Bay. |
| Leptoplana timida Heath & McGregor, 1912 | 1912 or earlier | | | rare as it is represented by only two individuals taken along the southern shore of Monterey Bay |
| Leptoplana saxicola Heath & McGregor, 1912 | 1912 or earlier | | | small flatworm, numerous individuals taken at a point a few miles south of the entrance to Monterey Bay, |
| Leptoplana inquieta Heath & McGregor, 1912 | 1912 or earlier | | | four specimens, captured about the low-tide limit among the rocks, and in one case among the rhizoids of Macrocystis in Monterey Bay, |
| Phylloplana litoricola Heath & McGregor, 1912 | 1912 or earlier | | | nine individuals, living on the under surface of stones below the medium-tide mark along the sourthern shore of Monterey Bay, |
| Aceros langi Heath & McGregor, 1912 | 1912 or earlier | | | single specimen taken on the southern shore of Monterey Bay. |
| Anciliplana graffi Heath & McGregor, 1912 | 1912 or earlier | | | several specimens of this species were collected in Monterey Bay and along the adjoining coast |
| Eurylepta aurantiaca Heath & McGregor, 1912 | 1912 or earlier | | | fairly common in Monterey Bay and the neighboring coast where it occurs under stones or crawling along the bottom in comparitively shallow water. |
| Euryleptodes cavicola Heath & McGregor, 1912 | 1912 or earlier | | | nine specimens taken at various points along the shores of Monterey Bay. |
| Euryleptodes pannulus Heath & McGregor, 1912 | 1912 or earlier | | | one specimen. |
| Euryleptodes phyllulus Heath & McGregor, 1912 | 1912 or earlier | | | several specimens taken on the shore of Monterey Bay. |
| Stylostomum lentum Heath & McGregor, 1912 | 1912 or earlier | | | six individuals taken near Monterey, at low-tide. |
| Amblyceraeus luteus Plehn, 1897 | 1897 or earlier | | | |
| Leptoplana californica Plehn, 1897 | 1897 or earlier | | | |
| Cylindrostoma triangulum Karling, 1962 | Sep 19, 1960 | 26 m | sand, stones | sand, stones and algae, dredged from about 26 m. |
| Austrorhynchus californicus Karling, 1977 | Apr 3, 1969 | 10 m | fine sand | in the kelp zone. |
| Scanorhynchus forcipatus Karling, 1955 | Sep 19, 1960 | 2-10 m | fine sand with mud | |
| Scanorhynchus forcipatus Karling, 1955 | Apr 3, 1969 | 2-10 m | fine sand with mud | |