Mercury Publications, Inc.

Mercury Publications (a.k.a. Mercury Press) was a magazine publishing company, owned and operated by Lawrence E. Spivak, which mainly published genre fiction in digest-sized formats. The focus of Spivak's line was on detective and mystery stories and novels, but it also included magazines about humor, fantasy, and true crime. The offices were located at 570 Lexington Avenue in New York, N.Y. https://en.wikipedia.org/wiki/Mercury_Publications