Carter AVS question

I have two ‘65 Darts with 235hp Charger engines. It’s been 50+ years since I worked on a Carter AVS, so I’m not an expert on them. Today I noticed that there are two holes on the front of the carb just above the butterflies that go straight through to unfiltered outside air. At first I thought that someone must have removed the plugs that should go there, so I checked the carb for my other carb. It is the same way. The car runs and idles ok, with good throttle response, the mixture screws work ok, and the idle vacuum is within specs. Is this the way this carburetor is built? Seems pretty strange to me.