| Amphiscolops sargassi Hyman, 1939 | Aug 1935 | | floating Sargassum | 'on floating Sargassum (whether of pelagic or of neritic origin unknown.' Not common, only 4 specimens from considerable amount of water and Sargassum. |
| Gnesioceros sargassicola (Mertens, 1832) | prior to 1939 | surface | Sargassum | taken alive on floating Sargassum. |
| Pseudoceros crozieri Hyman, 1939 | Jul-Aug, 1935 | | ascidian colonies | taken near or on ascidian colonies. |
| Leptoplana lactoalba Verrill, 1900 | 1898 | | stones and coral | under stones and corals on the reefs |
| Pseudoceros superbus (2) Lang, 1884 | 1900 or earlier | | stones | 'under stones at and just below low-tide, usually associated with a dark botrylloid compound ascidian or with a dark purplish sponge, with both of which it corresponds closely in color. |
| Pseudoceros pardalis Verrill, 1900 | earlier than 1900 | | stones | collected many years ago by Dr. Hartt Merriam and presented by him to the Museum of Yale University. |
| Macrogynium ovalis Meserve, 1934 | 1934 or earlier | | | occurs in the intestine of Stichopus sp. |
| Pseudoceros splendidus Stummer-Traunfels, 1933 | 1939 or earlier | | | apparently cosmopolitan. The type locality is the Mediterranean and the species has since been found at Bermuda (Hyman, 1939b) and the Galápagos Islands (Plehn, 1896). |
| Amaga expatria Jones & Sterrer, 2005 | 2005 or earlier | | | Bermuda. |
| Gigantea gouvernoni Jones & Sterrer, 2005 | 2005 or earlier | | | |
| Bipalium vagum Jones & Sterrer, 2005 | | | | |
| Amaga expatria Jones & Sterrer, 2005 | 1963 | | | |
| Amaga expatria Jones & Sterrer, 2005 | 1988 | | | |