Some Notes on the Genus Lepas Linné, 1767. (Subphylum Crustacea; Classis Cirripedia; Ordo Thoracica; Fam. Lepadidae.)

For the last twenty years several authors have been pointing out, that the species of the genus Lepas are very difficult to distinguish. The forms Lepas anatifera Linné and Lepas anserifera Linné especially cause trouble in identifying. It is often hard and sometimes even impossible to distinguish them by an examination of the shell pieces alone. The only distinguishing mark between the two species is the number of the filamentary appendages, which is two (seldom only one) for Lepas anatifera and four to six for Lepas anserifera. The other characters of the capituium used in most of the earlier keys are too variable to be used for accurate identifying. The number of the filamentary appendages may render good service too if one has to distinguish Lepas hilli Leach from Lepas anatifera Linné and Lepas pectinata Spengler from Lepas anserifera specimens with strongly furrowed valves. For this purpose a key based on the number of the filamentary appendages has been included in this paper.