TAXONOMY OF EUROPEAN SPECIES OF CASSAGNAUDIELLA AND BOURLETIELLA (COLLEMBOLA, SYMPHYPLEONA, BOURLETIELLIDAE)

The taxonomy of the European members of Cassagnaudiella and Bourletiel la (Collembola, Symphypleona, Bourletiellidae) is reviewed. The subgen us Cassagnandiella Ellis, 1975 is raised to generic rank with a new de finition. Specimens earlier considered to represent a transformed form of Bourletiella radula Gisin, 1946 are referred to Cassagnaudiella, a nd the application of 'phenotypic neutralization' within the group is considered erroneous. Four Bourletiella species and six Cassagnaudiell a species are described, five of the latter which are new: C. coeruleo vernalis sp. n., C. luteovernalis sp. n., C. cadiensis sp. n., C. cani gouensis sp. n., and C. trichroma sp. n.. A key to species is provided .