For the table of contents, check at the bottom of this post below the image.
The book is available at Sacred Texts Archive and Hathi Trust.
If you are curious about the various sources that Thomas used to compile the collection, you can consult the Preface; he lists many different sources, and emphasizes that "nothing has been inserted that is not genuinely traditionary." If you are curious about Wales and its cultural traditions, you can learn more at Wikipedia: Wales.
The Curse of the Pantannas
The Drowning of the Bottom Hundred
Elidyr's Sojurn in Fairy Land
Rhys and Llywelyn
Lowri Dafydd Earns a Purse of Gold
The Llanfabon Changeling
Why the Red Dragon is the Emblem of Wales
Lyn Cwm Llwch
The Adventures of Three Farmers
Cadwaladr and his Goat
The Fairy Wife
Einion and the Lady of the Greenwood
The Green Isles of the Ocean
March's Ears
The Fairy Harp
Guto Bach and the Fairies
Ianto's Chase
The Stray Cow
Bala Lake
The Forbidden Fountain
Tudur ap Einion
The Fairy Walking Stick
Dick the Fiddler's Money
A Strange Otter
Fairy Ointment
Pergrin and the Mermaiden
The Cave of the Young Men of Snowdonia
Einion and the Fair Family
St Collen and the King of Fairy
Helig's Hollow
Owen Goes A-Wooing
The Fairy Reward
Why Deunant has the Front Door in the Back
Getting Rid of Fairies
The Mantle of Kings' Beards
Pedws Ffowk and St. Elian's Well
Magic Music
Sili go Dwt
Another Changeling
A Fairy Borrowing
Treasure Seeking
The Richest Man
St. Beuno and the Curlew
The Cat Witches
The Swallowed Court
What Marged Rolant Saw
Ned Puw's Farewell
Pennard Castle
The Man with the Green Weeds
Goronwy Tudor and the Witches of Llanddons
Robin's Return
The Harper's Gratuity
Six and Four are Ten
Envy Burns Itself
The Bride from the Red Lake
A Fairy Dog
Grace's Well
The Fairy Password
St. Winifred's Well
The Ancients of the World
Nansi Llwyd and the Dog of Darkness
An Adventure in the Big Bog
The Pwca of the Trwyn
John Gethin and the Candle
Fetching a Halter
Dai Sion's Homecoming
Melangell's Lambs
Syfaddon Lake
The Power of St Tegla's Well
The Men of Ardudwy
The Parti-coloured Cow
Striking a Corpse Candle
Hu Gadarn
The Devil's Bridge
The Martyred Hound
Twm of the Fair Lies
Black Robin
Llyn Llech Owen
A Ghostly Rehersal
A Phantom's Funeral
Why the Robin's Breast is Red