Many thanks to Robert Weinberg for kindly granting me permission to use his cover scans.

NOT AT NIGHT

Edited by Christine Campbell Thomson: Published by Selwyn & Blount.

Not At Night (October, 1925)
More Not At Night (Sept. 1926)
You’ll Need A Night Light (Sept. 1927)
Gruesome Cargoes (July, 1928 )
By Daylight Only (Oct. 1929)
Switch On The Light (April, 1931)
At Dead Of Night (Nov, 1931)
Grim Death (Aug, 1932)
Keep On The Light (July, 1933)
Terror By Night (Aug., 1934)
Nightmare By Daylight (April, 1936)
Not At Night Omnibus (April 1937)

Arrow books published three paperback compilations from the series from 1960-62 as:

Not At Night (1960)
More Not At Night (1961)
Still Not At Night (1962)

CREEPS

Edited by Charles Lloyd (Charles Birkin): Published by Philip Allan.

Creeps (1932)
Shudders (1932)
Shivers (1933)
Horrors(1933)
Terrors (1933)
Quakes (1933)
Nightmares (1933)
Monsters (1934)
Panics (1934)
Powers Of Darkness (1934)
The Creeps Omnibus (1935)
Thrills (1935)
Tales Of Fear (1935)
Tales Of Death (1936)
Tales Of Dread (1936)