Both "pistol" and "revolver" frogs were used by the USN during the late flint, into the percussion and early cartridge periods.
Pistols were single shot muzzle loading or cartridge firearms.
Revolvers were, of course, multi shot revolving handguns.
Navy holsters/frogs and/or "buckets" were intended to only secure the firearm to the waist belt during GQ or battle. Weapons were always turned back into the Armory or QM aboard ship after the action. The USN did not need the full covering effect land forces need for their side arms.
Vol. III of " American Military Equipage, 1851 to 1872" by Todd, has some very nice illustration of Naval equipment. Including two types of "revolver' frogs that were common. One for Colt's and another one for Remington's.
I hope this information helps.
My best,
Blair