A book of variants for the game Lexicon, published by Waddingtons in 1935 or so. They had had great success with selling the original game, so they decided the market would like more variety. In effect, in modern terms, this book is an expansion as it adds lots of new rules that will need different strategy.
The 64-page booklet sold separately (red cover for one shilling) and advertised 25 variants. The pale blue/green version was included for free in first edition blue books sold in 1935, but has rules for only 23 variant games with the Lexicon deck: Bridge; Whist; Scramble; Dominoes; Cribbage; Poker; Stud Poker; Eights; Clock Patience; Brighton Patience; Dictionary; Riddance; Donkey; Criss Cross; Twister; One Better; Jumble; Tap and Grab; Mine; Don't Forget; Demon; Pay Up; and Teasers. (The red cover edition also includes Lexicon Newmarket and Lexicon Duplexicon.)