NEW SPECIES OF ZYZZYA, CORNULELLA, DAMIRIA, AND ACHELIDERMA (PORIFERA, POECILOSCLERIDA), WITH A REVIEW OF FISTULAR GENERA OF IOPHONIDAE

New sponge species belonging to the closely related fistular genera Zy zzya, Cornulella, Damiria, and Acheliderma are described from reef hab itats off the coasts of Colombia, Bonaire and Curacao in the southern Caribbean. With very few exceptions these sponges are small to tiny sp ecimens inhabiting crevices and other cryptic habitats; some may be ex cavating. For comparison both published and unpublished material belon ging to these genera from other parts of the world was examined, and t his yielded several nomenclatorial changes and a further three new spe cies from the Indian Ocean. The new species are: Zyzzya invemar (Carib bean), Cornulella santamartae (Caribbean), C. tyro (Seychelles), C. am irantensis (Seychelles), Damiria leonorae (Caribbean), D. toxifera (Se ychelles) and Archeliderma lisannae (Caribbean). All species belonging to these genera, as well as to the closely related Indo-Pacific genus Paracornulum, are briefly diagnosed. The genera and species of this g roup are found to be distributed over tropical and subtropical waters of all three oceans. The five genera were so far of controversial syst ematic allocation, although their close relationship with Cornulum was generally accepted. The recently revived family Iophonidae is demonst rated to be the likely assemblage for them. A brief survey of Iophonid ae genera is presented and a preliminary phylogenetic analysis of the fistular genera is attempted. Although several parts of the phylogenet ic relationships remain unsolved, it is nevertheless clear that in all genera the closest relatives are not found in adjacent areas, but are often disjunct.