158 
NoRMANj on Diatomaceae. 
P. pygrrKBtty Ehr. — Not uufrequent. Banks of River Hull. 
Ditch at Cottingham. In a water tub for poultry. Small 
ditch near River Hull, above Stoneferry. Near the Glass 
Houses, Dr. Munroe. 
P. bicepSj Greg. — Rare. Market Weighton Canal. 
P. garganica, Rabenh. — Frequent in fresh and brackish water. 
Ditch leading from Anlaby to Hessle Road. Humber 
Banks. Ditch at Cottingham. Harrogate. Ditch near 
River Hull. 
Stauroneis, Ehrenberg. 
S. Phoenicenteron, Ehr. — Common in fresh water. Nettleton. 
Cottingham. Saltersgate. Nearly pure in a boggy place, 
Skirlaugh. Risby Pond. Harrogate. Hornsea Deposit. 
Market Weighton Canal. 
S. gracilis, Ehr. — Not uncommon. Near River Hull. Net- 
tleton. Haltenprice. Humber Banks. Spring Ditch. 
Hornsea Deposit. 
S. acuta, Sm. — Rare. Not unfrequent in Risby Pond. 
Hornsea Peat Deposit. 
S. salina, Sm. — Frequent in brackish water. Pure near 
Stoneferry. Stallingbro\ Marsh Chapel. Tetney. 
Ditch near River Hull. Outlet Hornsey Meer. 
>S^. dilatata, Sm. — Rare in brackish water. Ditch near River 
Hull, beyond Stoneferry. Tetney. 
S. crucicula. Sm. — Rare in brackish water. River Hull. 
S. anceps, Ehr. — Frequent in fresh water, though never abun- 
dant. Spring Ditch. Frequent near Cottingham. Be- 
verley. Nettleton, in Clay Pit. Wawne. Harrogate. 
Haltenprice. Hornsea Deposit. 
S. linearis, Ehr. — Frequent in fresh water, though always 
much mixed. Killinghall. Beverley. Very frequent 
near Cottingham. Market Weighton Canal. 
S. pulchella, Sm. — Very frequent in Ascidians. Hornsea 
Sands. Dredgings off Flambro' Head. 
Pleurosigma, Smith. 
P. decorum, Sm. — Rare. Not unfrequent in a Dredging off 
Flambro^ Head. 
P. rigidum, Sm. — Rare in a Dredging taken off Flambro' 
Head. North Humber Bank, Dr. Munroe. 
P. elongatum, Sm. — Abundant in salt water. Ditch leading 
from Anlaby to Hessle Road. Marfleet. Outlet Hornsea 
Meer. Ditch near River Hull. Tetney. 
P. intermedium, Sm. — Not unfrequent in salt water. Victoria 
Dock Timber Pond. Timber Pond, Grimsby. 
