The present situation in the taxonomy of this group is quite unsatisfactory. Up to now there is no agreement among authors on the question what should constitute a genus in this family. Verhoeff in particular has created a number of small genera among Australian spirobolellids, which, because the earlier described species were not taken into account, have not found general acceptance. In this catalogue I have synonymized most of these small generic categories with the genus Spirobolellus. For the present purpose I do not follow Hoffman, 1999, in uniting Spirobolellus with the Neotropical genus Microspirobolus Silvestri, 1898, and its synonyms . Besides geographical reasons I guess that sooner or later several generic categories may be distinguished in both these genera. I must admit, however, that at present I cannot give any decisive morphological character for distinguishing the many American from the Indo-Australian species. In this regard there is some parallel between the Spirobolellidae and the dominant generic categories of the South American and Australian Rhinocricidae.