Particle collection by the ALT-II belt limiter in the TEXTOR-94 tokamak is exclusively limited to the parallel outflux because the scoop walls that are oriented parallel to the field lines obstruct the poloidal E×B mass flow. With normal B tor direction (E×B towards the scoops), a threefold decrease of plenum pressure is measured during negative biasing, while with reversed B tor (E×B away from the scoops), a 60% pressure increase is observed. This behaviour is exactly opposite to that observed in X-point divertors. A simple fluid model explains this apparent contradiction, and gives good quantitative agreement with measurements of the parallel Mach number in the SOL. The essential physics is governed by the Bohm-Chodura criterion.