Studies on Marine Algae of the British Isles:Ceramium shuttleworthianum(Kütz.) Silva

The species was first distinguished by Carmichael, asCeramium acanthonotum,in his unpublishedAlgae Appinensis,the manuscript of which is now preserved at the Herbarium of the Royal Botanic Gardens, Kew. Harvey (in Hooker, 1833), in publishing Carmichael's description, regarded the species merely as a variety ofC. ciliatum.Agardh (1844) raised the variety to specific status, and it is asC. acanthonotumthat the species has been known generally. Kiitzing (1841),1in a revision of the genusCeramium,had described the entity independently asAcanthoceras shuttleworthianum;the specific epithetshuttleworthianumhas priority overacanthonotum[see Article 60 of the International Code of Botanical Nomenclature (Lanjouw, 1956)]. The priority of the epithetshuttleworthianumwas indicated, independently, by both Silva (1959) and Dixon (1959); of the two publications, that by Silva is the earlier.