62 
Norman, on Diatomacece. 
A. n. s. with capitate extremities. Growing on wall in a Fern 
and OrcMd stove. 
A. quadrata, Greg. — E-are. Ascidian gatherings. 
A. arenaria, Donk. — Rare. Sands, Hornsea. 
A. littoralis, Donk. — Rare. Sands, Hornsea. 
A. crassa. Greg, — Rare. In Ascidians. 
CoccoNEis, Ehrenberg. 
C. PediculuSy Ehr. — ^Very common in most fresh-water 
gatherings. Pure, Cottingham Beck, on Cladophora 
Waterworks reservoir. Beverley. River Hull. Cot- 
tingham, &c. 
C. Placentula, Ehr. — Very frequent. Cottingham. Halten- 
price. Wawne. Pure on Cladophora, Harrogate. Water- 
works reservoir. 
C. Thwaitesii, Sm. — Rare. Ditch, Cottingham-road. Springs, 
Newbald. 
C. Scutellum, Ehr. — Common on Cladophora rupestris. Filey. 
Flambro' Head. Stomachs of Ascidians. 
C. diaphana, Sm. — Rare. Hornsea Deposit. Brackish ditch. 
Marsh Chapel. 
CosciNODiscus, Ehrenberg. 
C. minor, Ehr. — Rare. Ascidians. 
C. minor, Kiitz. — Rare. In a slide from the Humber gathered 
by Dr. Redfern in 1853, and sent to me by Professor 
Arnott. 
C. radiatus, Ehr. — Common in Ascidian gatherings, Dredg- 
ings off Flambro^ Head. Rare in Market Weiighton 
Canal. Rare in Reservoir Waterworks, where the salt 
water unfortunately sometimes has access. 
C. eccentricus, Ehr. — Very common in Ascidian gatherings, 
often very pure. 
C. Concinnus, Sm. — Frequent in Ascidians, sometimes very 
large. 
C. perforatus, Ehr.? — Ascidians. Very rare. 
C. ovalis. Roper. — Very rare in Ascidian gatherings. 
C. Normani, Greg. — Frequent in Ascidian gatherings. 
C. Labyrinthus, Roper. — Very rare in Ascidian gatherings. 
C. centralis, Ehr. — Frequent in Ascidians. 
EupoDiscus, Ehrenberg. 
E. Argus, Ehr. — Not unfrequent in Ascidians. Dredgings 
off Flambro' Head. 
