Digeneans from intertidal molluscs of SW iceland

The fauna of digenean daughter-sporocysts, rediae, cercariae and metacercar iae infecting molluscs Littorina spp., Onoba aculeus, Nucella lapillus and Epheria vincta has been studied in the Skerjafjordur and Grindavik regions of SW Iceland. In total, intramolluscan stages of 19 digenean species were recorded; 14 of them are new for Iceland and one of them, a microphallid na med Cercaria islandica I, was unknown. A description of this new microphall id cercaria is provided. In addition, the identification and separation of the intramolluscan stages of some microphallid, renicolid and echinostomati d species are discussed. Consideration is given to difficulties encountered when identifying digenean species found on the coasts of European countrie s. Problems have arisen largely because larval and adult stages have been d escribed and named independently and in isolation, synonyms are common and many "definitive" descriptions are inadequate or incomplete.