Abstract: Screening apparatus provides improved dewatering of liquid slurries by flowing the slurry across a generally parabolically shaped perforate screening surface inclined at an angle to the horizontal. The angularity of the generally parabolically shaped screening surface is adjustable at any time or at any point in the screening process. The preferred embodiment of screen assembly, which incorporates multiple bars extending generally transversely of the flow direction of the slurry, is fabricated by a method which facilitates the provision of screening slots of different widths in different areas of the screening surface.