In this paper we examined in detail an example of bounce-phase-clustered ions such as earlier reported by McIlwait (1976) and Quinn and McIlwain (1979). The cluster has small pitch angle, but investigation of the energy time dispersion properties of the cluster reveals that it was formed at the equator. The acceleration region extended over about 2.4 RE along the field direction. We suggest that the ion cluster is set up by acceleration during a transient convection surge, and we discuss the properties of such a process.