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Summary
A revised classification of the Oligochaeta and Clitellata accords with the present consensus that leeches and branchiobdellids are contained within the Oligochaeta. As a result the name Oligochaeta is redundant as it is synonymous with Clitellata. The former group may still be informally termed oligochaetes or oligochaetous annelids however. Reference: Jamieson, B.G.M. 2006. Non-leech Clitellata. (with contributions by Marco Ferraguti). Pp. 235-392. In Reproductive Biology and Phylogeny of Annelida. Series Editor B.G.M. Jamieson. Volume 4. Editors Greg Rouse and Fredrik Pleijel. Science Publishers, Enfield, New Hampshire, U.S.A. Jersey, Plymouth, U.K. ISBN 1-57808-313-3.