10 LIVERPOOL BIOLOGICAL SOCIETY. 
Rhizosolema (Ehr.) imbricata, Brightw. Surface of Dee, 
rare. 
fh. setigera, Brightw. Connah’s Quay, rare. 
R. styliformis, Brightw. Connah’s Quay, rare. 
R. wighamit, Brightw. Surface of Dee, rare. 
Schizonema (Agardh.) crucigera, W.Sm. Helsby Marsh, 
common. 
S. eximium, Th. Mostyn, rare. 
S. helmintosum, Greg. Helsby Marsh, rare. 
S. vulgare, Th. Helsby Marsh, common. 
Scoliopleura (Grun.) latistriata, Breb. Mostyn, common. 
S. tumida, Breb. Mostyn, common. 
Skeletonema (Grev.) costatum, Grun. Surface of Dee, rare. 
Stauroneis (Ehr.) acuta, W.Sm. Queen’s Ferry, very rare. 
S. salina, W.Sm. Connah’s Quay, rare. 
S. linearis, W.Sm. Helsby Marsh, common. 
Stephanopyxis (Khr.) turris, Grey. Surface of Dee, rare. 
Striatella (Kutz.) unipunctata, Ag. Helsby Marsh, very 
rare. It was a long time before I found this form, which 
is so common on the south coast. 
Surirella (Turp.) constricta, W.Sm. Burton Marsh, rare. 
S. crumena, Breb. Helsby Marsh, rare. 
S. gemma, Ehr. Mostyn, very common. 
S. fastuosa, Ehr. Mostyn, rare. 
S. salina, W.Sm. Railway bridge, very common. 
S. splendida, Kutz. Helsby Marsh, rare. 
S. striatula, Turp. Mostyn, very common. 
Synedra (Khr.) affinis, Kutz. Hiulbre Island, very 
common. 
S. affaus, var. arcus, Kutz. Helsby Marsh, very 
common. 
S. fulgens, W. Sm. Isle of Man, common. 
