Meteor stream membership criteria us ed in evaluating potential associations between individual meteor orbits and the mean orbit of a stream are discussed on the basis of precise photographic orbits of some meteor streams (the Taurids, Geminids and Perseids). Serious shortcomings of the D-criterion are disclosed and suggestions on a more relevant use of the criteria for estimating stream memberships are presented, with attention paid to the distributions of the orbital elements of the streams.
The Taurid meteor complex associated with P/Encke Is studied on the basis of relevant photographic and radar orblts. Orbltal characteristlcs, radiants and durationa of the postperihelion
showers are compared with correspondlng theoretlcal values derived from the observationn of the preperihelion Taurlds, Reality of the proposed assoclatlons of mlnor showers with the Taurld complex and the total duratlon of Its actlvilty are evaluated and discussed. Some of the associated showers the Northern and Southern X Orionids, Northern Piscids and Southern Arietids) are confirmed to be In fact parts of the Taurid shower itself.