Integrative taxonomy studies have allowed us to clarify some taxonomic problems in cryptic species within species of InachusWeber, 1795 with two protogastric tubercles found in European waters. Several morphotypes of Inachus phalangium (Fabricius, 1775) are recognized, and a new species is described from the Atlantic coast of the Iberian Peninsula, for which distribution data are provided. Furthermore, two Inachus cf. thoracicus specimens with a unique sternal morphology were collected from Málaga Spain, but their preservation in formaldehyde prevented molecular analyses. Specimens of I. guentheri (Miers, 1879) have been re-examined and the validity of previous reports from tropical and subtropical Atlantic waters is discussed. These results allow us to separate and clarify the status of species within this group. An identification key for Inachus species with two protogastric tubercles is also provided.