STUDY OF 2 SPECIFIC CASES IN ZOOLOGICAL T AXONOMY - EXAMPLES IN THE BRYOZOANS

The genus Alcyonidium (ctcnostomatous bryozoans) includes various comp lexes of cryptic species: mytili, polyoum, gelatinosum and hirsutum. I n some cases, the original descriptions are insufficient, and no origi nal material of these species has been preserved. This caused some con fusion in the literature, leading to attemps to clarify the systematic problems. Two <<specific cases>>, apt to occur in all zoological grou ps, were identified in the genus Alcyonidium : 1 - designation of a se cond neotype, originating from an area nearer to the presumed original locality of the initial material, than a previously-designated neotyp e and corresponding in fact to another species; 2 - rehabilitation for a common species of a taxonomic name, rarely used in the past 225 yea rs, to the detriment of another name widely for fast 140 years (invoki ng anew the problem of the Nomen oblitum, recognized in a previous edi tion of the International Code of Zoological Nomenclature). Theorical and practical solutions to these problems are proposed.