In the UK it's called a donut ring - soft rubber clamped tight around the syphon tube and the pan by a flat plate drwan down by two wing nuts, one each side underneath at the back.
Sometimes you can cure the leak by just tightening the wing nuts.
Squint sideways along the join line and you should just be able to see the squashed up rubber washer, a thin black line.
Good luck...
Peccavi
July 2009