The aim of this study is to describe Rhaphidostyla fistuloxifera sp. nov., a new cryptogenic species of Halichondriidae with disjunct distribution from Brazil to Hawaii, using morphological and molecular data. Molecular phylogeny analysis showed that the new species belonged to the same clade as H. kitchingi (from the Celtic Sea), the type of Rhaphidostyla, which is currently regarded as a junior synonym of Hymeniacidon. Accordingly, we propose to resurrect the genus Rhaphidostyla, based on morphological and molecular evidence, to accommodate the new species and other closely related mismatched Hymeniacidon species which belong to the same distantly related clade. Rhaphidostyla is redefined by the presence of profusely bifurcated fistules as a key diagnostic feature, shared by R. kitchingi, R. pierrei (California) and the new species (Brazil and Hawaii), in combination with typical (subtylo-)styles, with an acerate point, and sometimes oxeas. Rhaphidostyla fistuloxifera sp. nov. in turn differs from the type species and all other known Halichondriidae by possessing stout acerate choanosomal oxeas in combination with relatively longer and thinner (subtylo-)styles. Morphological and genetic analyses, including ITS2 and large ribosomal subunit sequences, confirmed the conspecificity of Brazilian and Hawaiian populations of the new species previously assigned to Hymeniacidon gracilis (Hentschel, 1912). New genetic sequences of Rhaphidostyla and other Halichondriidae species from Brazil, Hawaii and the Celtic Sea are also provided. Our work contributes to the understanding of global marine sponge diversity, by correcting past identifications and reviving a genus described nearly 100years ago