| Diopisthoporus longitubus Westblad, 1940 | 1958-1961 | intertidal | coarse sand, fine shell gravel | 2 specimens at LWN. | 
| Dolichomacrostomum uniporum Luther, 1947 | 1958-1961 |  | medium sand with fine shell gravel | rare at ELWS. | 
| Brinkmanniella macrostomoides Luther, 1948 | 1958-1961 |  | fine shell gravel, coarse sand | occasional at halfway between LWN and MTL. | 
| Proxenetes (Proxenetes) simplex Luther, 1948 | 1958-1961 |  | coarse sand, fine shell gravel | occasional at LWN. | 
| Tvaerminnea karlingi Luther, 1943 | 1958-1961 |  | coarse sand, fine shell gravel | occasional at LWN.  Note: previously other authors Luther, French,  and Ax found this species in low salinity water. | 
| Vejdovskya pellucida (Schultze, 1851) | 1958-1961 |  | fine shell gravel | occasional at HWM. | 
| Monocelis lineata (Müller, 1773) | 1958-1961 |  | coarse sand with fine shell gravel. | one specimen at LWN. | 
| Nematoplana coelogynoporoides Meixner, 1938 | 1958-1961 | intertidal | fine shell gravel, coarse sand | LWN, common. | 
| Nematoplana coelogynoporoides Meixner, 1938 | 1958-1961 | intertidal | fine shell gravel, coarse sand | MTL, frequent. | 
| Nematoplana coelogynoporoides Meixner, 1938 | 1958-1961 | intertidal | fine shell gravel | HWN, from pool, common. | 
| Parotoplana capitata Meixner, 1938 | 1958-1961 | intertidal | fine shell gravel, coarse sand | MTL, common. | 
| Parotoplana capitata Meixner, 1938 | 1958-1961 | intertidal | fine shell gravel, coarse sand | HWN, from pool, common. | 
| Polystyliphora filum Ax, 1958 | 1958-1961 | intertidal | medium sand, fine shell gravel | LWN 1/2 MTL, 10 cm below sand surface, rare. |