Notes on the systematics, morphology and biostratigraphy of fossil holoplanktonic Mollusca, 13. Considerations on a subdivision of Thecosomata, with the emphasis on genus group classification of Limacinidae

The families Limacinidae, Cavoliniidae and Peraclididae (Gastropoda, Thecosomata) are raised in rank to Limacinoidea, Cavolinioidea and Peraclidoidea, respectively, and currently recognised subfamilies of the Cavoliniidae are given full familial status, viz. Creseidae, Cuvierinidae, Clioidae and Cavoliniidae. A preliminary genus group classification of the Limacinidae is proposed, mainly on morphological shell features; a new genus, Currylimacina n. gen., is introduced.