De Haan (1833, p. 22-23, tab. B (Eudora) tenax (mouthparts)) gives the following latin description of his subgenus Eudora: "Os quadratum. Max. 5arum articuli secundi paralleli, medio in longitudinem sulcati, apice truncati; articuli tertii dilatati, margine superiore emarginati; articuli apicales abbreviati1). Max. 3iarum laciniae externae supra medium, paulum dilatatae, apice emarginatae. Max. 2arum lobi interni in laciniis interioribus externis multo breviores. Thorax vix dimidio latior quam longior, dorso convexus. Chelae crassae, in utroque sexu inaequales, sinistra minor. Abdomen in utroque sexu 7-articulatum; in maribus angusto-parallelum; articulus tertius prioribus latior; articuli versus apicem sexti sinuato-angustiores; sextus quadratus; Septimus trigonus. In feminis oblongo-ovatum, a basi latescens; articulus sextus quinto duplo latior; septimus rotundatus. O c u l i vix tertia parte latitudinis thoracis distantes. Antennae oculorum canthis approximatae, flagello brevissimo. CANC. (EUDORA) TENAX Ruppell. — IMPRESSUS Lamarck n. 9. — INCISUS. n. sp. Mus. Reg. Bat." When studying the Xantho specimens of the Leiden Museum, I noticed among them in the dry collection, a ♀ without mouthparts and a set of mouthparts from Mauritius, Museum Paris, both labelled Xantho (X.) impressus (Lam.) and both bearing an old label "Cancer (Eudora) impressus Lamarck, Isle de France, Mus. Gal." Now the presence of the set of mouthparts as well as the writing on the old label leave no doubt whatever to the fact that this is the specimen examined by De Haan and enumerated on page 23 of the Fauna Japonica. This specimen, however, is