p. 115-210 : ill. ; 26 cm.Includes bibliographical references (p. 200-207) and index.The world genera of Lymexylidae (Coleoptera: Cucujiformia: Lymexyloidea) are revised, including descriptions of two new genera. All described species are given generic assignments. Seven genera are recognized and assigned to three subfamilies: Hylecoetinae Boving and Craighead, 1931, including Hylecoetus Latreille; Lymexylinae Boving and Craighead, 1931 (sensu novo), including Lymexylon Fabricius and Atractocerus Palisot de Beauvois (including Raractocetus Kurosawa, new synonym, Hymaloxylon Kurosawa, new synonym, Arractocetus Kurosawa, new synonym, and Fusicornis Philippi); and Melittomminae, new subfamily, including Australymexylon, new genus, Melittomma Murray, Melittommopsis Lane, and Protomelittomma, new genus. Neohylecoetus Kurosawa is synonymized with Melittomma Murray, and Hylecoetopsis Lane is excluded from the Lymexylidae (and presumed to belong to the Cleridae). Species of the endemic Australian genus Australymexylon are revised and include A. australe (Erichson) (transferred from Lymexylon) and A. fuscipennis (Lea) (Hylecoetus). Hylecoetus linearis Lea and Lymexylon adelaidae Blackburn are synonymized with Australymexylon australe. Species level taxonomic changes include the following: Hylecoetus cossis Lewis, H. matsushitai Kono, and H. cribricolle (Fairmaire) are all synonymized with H. dermestoides (L.); Melittomma javanus (Kurosawa) (Neohylecoetus), M. pervagum (Olliff) (Hylecoetus), M. philippensis (Kurosawa) (Neohylecoetus), and M. vigilans (Lea) (Hylecoetus) are new combinations (but see Kurosawa, 1985); Melittommopsis validum (Schenkling) (Melittomma), M. ruficolle (Pic) (Melittomma), and M. abdominale (Pic) (Melittomma) are new combinations; and Protomelittomma insulare (Fairmaire) (Melittomma) is a new combination. For each genus, the following are given: a habitus drawing; illustrations of important characters; diagnosis; description of a representative species; list of species included; summaries of cladistic relations, geographic distributions, fungus hosts, arboreal hosts and bionomics; and a discussion. The cladistic relations among the genera are discussed, and my hypothesis is summarized as follows: (Hylecoetus + ((Lymexylon + Atractocerus) + (Australymexylon + (Protomelittomma + (Melittomma + Melittommopsis))))). The geographic history of the family is discussed. A key to and diagnoses of world subfamilies and genera are given, as well as discussions about the constitution of Lymexyloidea, natural history and economic importance of Lymexylidae, a detailed account of the morphology of Hylecoetus dermestoides, and a reclassification of supraspecific taxa