| Microstomum davenporti Graff, 1911 | between May and Aug 1907 |  |  |  | 
| Proxenetes modestus Graff, 1911 | between May and Aug 1907 |  |  | 5 specimens | 
| Woodsholia lilliei Graff, 1911 | between May  and Aug 1907 |  |  |  | 
| Phonorhynchus helgolandicus (Metschnikow, 1865) | between May  and Aug 1907 |  |  |  | 
| Plagiostomum stellatum Graff, 1911 | between May and Aug 1907 |  |  | Grass Island in Zostera | 
| Plagiostomum morgani Graff, 1911 | between May and Aug 1907 |  |  |  | 
| Myrmeciplana elegans Graff, 1911 | prior to 1911 |  | coarse sand |  | 
| Myrmeciplana sp. Bush, 1964 | 1963 |  |  | may be Myrmeciplana, "but have a pair of eyes in most cases". | 
| Euplana gracilis (Girard, 1850) | 1935 or earlier |  |  | secured specimens from invertebrate staff at Woods Hole in 1935.  Found in abundance in the Eel Pond on wharves and pilings among masses of hydroids and sponges,. |