Turbellarien der Gattung Promesostoma von der nordamerikanischen Pazifikküste

Abstract

Two new species of the genus Promesostoma, P. infundibulum nov. spec. and P. hymanae nov. spec., are described from the mesopsammal of the San Juan Archipel (Washington, USA). They are closely related to P. dipterostylumKarling from the Californian coast. These three species have a differentiated seminal receptacle with special cuticular structures, which represents a remarkable synapomorphy. The cuticular connection between the stylet and the seminal receptacle was unknown until now in the organization of turbellarians. © 1968 Biologischen Anstalt Helgoland.