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Ricklefs (1980) suggested the use of neontological data to distinguish between puncuated equilibrium and gradualism as modes of evolution. This paper investigates his model and finds it contains oversimplifications that make any test difficult. We modify his model slightly and use it as a limited test of punctuated equilibrium by large morphological shifts at speciation. This test is applied to a data set of 110 species from two families of bats, the Emballonuridae and the Molossidae. We find no evidence of consistently large morphological shifts at the formation of subspecies, species or genera.