The evolution of character states in a number of characters, mainly morphological ones, in the Terebellomorpha is discussed. The current use of meristic characters in classifications is discouraged. On the basis of the character states it is attempted to identify monophyletic groups within the order. The consequences to the taxonomy of the order are discussed. The connections of the order with other polychaete groups are discussed. It is concluded that the families Bogueidae and Sabellariidae should not be placed within the Terebellomorpha. One new species is erected (Auchenoplax rullieri
, based on an existing description). A number of new tribi and one new subfamily are proposed. The phylogeny of the Terebellomorpha is discussed, and it is suggested that the errant sister-group of a group of sedentary polychaete orders including the Terebellomorpha should be sought within the Eunicemorpha. A catalogue of the terebellomorph taxa with a limited number of new names (replacing homonyms) and new combinations is given. Definitions of suprageneric taxa are given, along with references to descriptions of all taxa and listings of the biogeographical regions in which the individual taxa occur. A combined reference list and bibliography of the Terebellomorpha including ca 770 references, covering ecology and physiology as well as systematics an faunistics, is given.