The Arkham House edition and the 1950 Museum Press reprint are the only complete collections. The two Belmont editions have nine stories each and combined they drop A Visitor From Egypt; Bridgehead; Second Night Out. The two Panther editions combined have all 21 stories.
One each of the Belmont and Panther editions retain the title The Hounds of Tindalos though, respectively, they reprint only 9 and 11 stories. DO NOT MERGE.
No statement of printing or edition.
Colophon states 2500 copies were printed. Actual number is 2602 copies per S.T. Joshi's Sixty Years of Arkham House.
Derleth Thirty Years of Arkham House: 14.
Joshi Sixty Years of Arkham House: 14.
Jaffery The Arkham House Companion: 16.
Nielsen Arkham House Books: 14.