of the agitator 16 a plurality of inlet apertures or openings 42 are provided through an upper wall 44 of the skirt to allow wash liquid to enter the spiral channel 40 the agitator may also have a skirt construction as shown in ser no 294 299 or other type of liquid pumping agitator the barrel portion 26 of the agitator 16 defines an annular space or channel 46 between the inner wall 36 and outer wall 34 the annular barrel channel 46 communicates with the spiral skirt channel 40 at the base of the barrel portion shown generally at 48 the top of the inner wall 36 terminates below the top of the outer wall 34 in a top wall 50 which has a central aperture 52 therethrough a splined portion 53 of a drive shaft 54 mates with a cylindrical splined portion 56 of top wall 52 and is used to drive the agitator 16 in an oscillatory motion the agitator 16 is secured to shaft 54 by means of appropriate fastening means 58 such as a bolt screwed into the splined end 53 of the shaft 54 the outer wall 34 of the agitator 16 continues upwardly beyond the top wall 50 of the inner wall 36 and terminates at a top end 60 which defines a circular opening 62 as best seen in the enlarged view in fig3 above the top wall 50 of the inner wall 36 there is provided a generally cylindrical passageway 64 disposed vertically and having an enlarged lower opening 66 and a top opening 68 the cylindrical passage 64 communicates with the.