A higher-level classification of Nemertea has been updated based on insights from recent phylogenetic studies. According to this classification, the phylum includes two superclasses (Pronemertea and Neonemertea), three classes (Palaeonemertea, Pilidiopho-ra,

An updated taxonomic review of Nemertea present in the Palaearctic is presented in this chapter. Dichotomous identification keys to the lowest justifiable taxonomic level based on the most recent literature are provided. These are coupled with the necessary

The deep-water bathypelagic nemertean Nectonemertes mirabilis, previously found in the Atlantic and Pacific oceans, was confirmed for the first time in the Gulf of Mexico. This new record is represented by a juvenile male collected by a stratified plankton