It's an Ortgies auto pistol, and was one of Germany's higher quality pocket autos.
The Ortgies was a finely finished pistol, with a very well finished interior.
The Ortgies was made from around 1919 up into the mid 1920's.
These were made in .25, .32, and .380.
The earlier guns were made by Ortgies & Co, in Erfurt, after 1921 they were made by Deutsche Werke.
The early grips had a stylized "O H" logo for Heinrich Ortgies, later guns had a logo that was a mythical animal that formed the letter "D".
Very late models also had an extra safety lever.
The Ortgies was very heavily imported into South America and the US in the post-war years, and was a popular pistol in it's day.
Unable to compete with the small Colt autos in America, and the Walther and Mauser in Germany, Ortgies folded.
It was famous for using no screws in it's design, and for being the most difficult pistol in the world to reassemble, UNLESS you know the "secret".
The unusual grip safety has a button that when pressed, allows the grip safety to spring out putting the gun on safe.
When depressed, the safety will allow the gun to fire.
To reapply the safety, the button is again pushed.
Another unusual feature is the firing pin acts as the ejector.
Disassembly isn't difficult, but reassembly IS.
To disassemble, remove the magazine.
Pull the slide back until the rear of the slide serrations line up with the rear of the frame.
Press in on the grip safety and lift the rear end of the slide up, then push it forward and off the frame.
The striker and spring are dropped out of the slide.
The barrel can be removed by twisting it counterclockwise to unlock it from the frame, but it's better left in place.
The grips can be removed by reaching inside the magazine well with a screwdriver and pressing the grip latch in the rear of the magazine well.
CAUTION: The grips are fragile and break easily. Unless necessary, leave them in place.
To reassemble:
The gun CANNOT be reassembled unless you know the "secret" which is to turn the striker into a small cut on the slide.
Put the barrel back in place, and be sure it's properly aligned with the frame.
Replace the recoil spring over the barrel.
Put the striker and spring in place in the slide, then push forward and turn the lug on the striker into the tiny cut in the slide.
Hold a cloth over the rear of the slide, since the tinniest bump will jar the assembly loose and it will shoot out with great force.
VERY carefully insert the front of the slide over the barrel, pull it back and press down until it locks onto the frame.