Cymodoce truncata (Leach, 1814), the type species of the genus, C. zanzibarensis (Stebbing, 1910) and C. richardsoniae (Nobili, 1906) are redescribed based on type specimens or topotypic material, and a neotype is designated for Cymodoce richardsoniae. A revised generic diagnosis and description is provided for the genus Cymodoce. Cymodoce delvarii sp. nov. is described from the subtidal zone o...

Gnorimosphaeroma oregonense (Dana, 1852) is revised, a male neotype designated, photographed, and illustrated; the species occurs from Vancouver British Columbia to central California coast. 16S-rDNA sequences (~650 bp) for all available ethanol preserved of were used hypothesize their relationships. Our analyses revealed sister taxon relationship between fully marine G. brackish freshwater spe...

Dynoides canadensis sp. nov. is described from the south-western coast of British Columbia, Canada. This species differs its closely related species, D. elegans (Boone, 1923) ), by presence a smooth pleotelson without prominent rounded tubercle on basal part pleotelsonic sinus, sinus wall lacking crenulation; in having penial processes length 7.7 × width and acute distal apex instead 2.3 blunt ...

Cymodoce waegelei sp. nov. is described from the subtidal zone of the Iranian coasts of the Persian Gulf using both morphological and molecular data. C. waegelei sp. nov. is most similar to C. tribullis Harrison & Holdich, 1984 from Australia, Vietnam and Singapore. Analysis of DNA barcodes and nuclear 28S rDNA: D8 expansion segments clearly support the existence of two distinct species. Cymodo...