The CTL-1 was a turretless tank armed with a single machine gun in a ball mount in the right side of the hull front. It was a private venture by Marmon-Herrington and was based on their TA series of light tracked tractors. The CTL-1 did not see service with the US, but was sold to Iran.
Crismon, Fred W. U.S. Military Tracked Vehicles. Osceola, WI: Motorbooks International, 1992.
Nuyt, A.F. "tanks." Overvalwagens! 13 Feb 2020 <https://web.archive.org/web/20060414173105/http://www.overvalwagen.com/tanks.html>.
Kirk, William. "U.S. Light Tanks." TANKS! 13 Feb 2003. 13 Feb 2020 <https://web.archive.org/web/20120212011858/http://mailer.fsu.edu/~akirk/tanks/UnitedStates/lighttanks/LightTanks.html>.