Comic Title: Detective Comics #31
Publisher: DC (Detective Comics, Inc.)
Address: 480 Lexington Avenue, New York, NY
Cover Date: September 1939
Approx. On Sale Date: August 10, 1939 Copyright Date July 30, 1939
Source: Library of Congress, Periodicals 1939
Until 1958 DC did not report actual on sale dates to the copyright office
The publication dates listed in LoC records are NOT release dates.

Frequency: Monthly
Cover Price: $0.10
Page Count: 64
Editor: Vincent A. Sullivan

Title: "The Mammoth Mystery"
Pages: 6

Feature(s):
Speed Saunders

Artist: Fred B. Guardineer