Norman, on Diatomacem. 
65 
S. ovata, Kiitz. — V ery frequent in brackish or fresh water. 
River Hull. Skirlaugh. Dairycoats. Nearly pure_, 
North Humber Bank. Cottingham, nearly pure. Harro- 
gate. Victoria Dock Timber Pond. 
S. salina, Sm. — Rare. Banks of River Hull. 
S. pinnata, Sm. — Not uncommon in fresh and even in 
brackish water J but never abundant. RisbyPond. Cot- 
tingham. Haltenprice. Ditch near River Hull. Horn- 
sea Deposit. 
S. angusta, Kiitz. — Rare. Stoneferry Lane. Dr. Munroe. 
S. Crumena, Breb. — Rare. Boggy Ditch, Saltersgate. Birk 
Craggs/^ Harrogate. Ditch at Haltenprice. 
S. apiculata, Sm. — Rare. Boggy Ditch, Saltersgate. 
S. minuta, Breb. — Rare. Thornton-le-Moor, Mr. Robt. Har- 
rison. Victoria Dock Timber Pond, Dr. Munroe. 
Tryblionella, Smith. 
T. gracilis, Sm. — Not uncommon in brackish water. Stone- 
ferry. Humber Banks. Hornsea Deposit. Market 
Weighton Canal. Very abundant and fine in a small 
Ditch northward of Stoneferry. 
T. marginata, Sm. — Not uncommon in brackish and fresh 
water. Stallingbro\ River Hull above Stoneferry. 
Outlet Hornsea Meer. Haltenprice. Market Weighton 
Canal. Pond near Stepney. 
T. constricta, Greg. — Rare. Ascidians. 
T. punctata, Sm. — Rare in brackish water. M arket Weighton 
Canal. Humber Bank, in slides sent me by Professor 
Arnott, collected by Dr. Redfern in 1853. Pond, Stepney, 
Lane. 
T. acuminata, Sm. — Not uncommon in brackish water. Rare 
in fresh water. Ditches near Stallingbro\ Cottingham. 
Timber Ponds, Mr. Robt. Harrison. 
T. angustata, Sm. — Rare. Market Weighton Canal. Be- 
verley Parks. Anlaby-Road, Dr. Munroe. Thornton-le- 
Moor. 
T. apiculata, Greg. — Frequent in a gathering, Patrington. 
T. Scutellum, Sm. — Very rare. North Humber Bank, Mr. 
Robt. Harrison. 
Cymatopleura, Smith. 
C. Solea, Sm. — Very common in fresh- water ditches. Skir- 
laugh. Hornsea Deposit. Wawne. Reservoir Water- 
works. Very abundant near Cottingham. Haltenprice. 
Spring Ditch. Beverley Parks, &c. 
