A magnetic bubble memory includes a planar magnetic film containing a plurality of magnetic bubbles which move in response to a magnetic field that rotates the film's plane; and further includes an improvided mechanism for detecting the bubbles comprised of: a pair of elongated magnetoresistive members that lie over the film alongside of one another; the members having fingers that extend towards each other along the direction of elongation; the fingers of one member being interdigitated with the fingers of the other member such that they mesh together but do not touch; the fingers being interdigitated at angles of less than 180° so that magnetic poles which attract the bubbles are sequentially induced in the fingers of only one member, in the fingers of both members, and in the fingers of only the other member by each rotation of the field.