Opinion 556 Designation under the Plenary Powers of a type species in harmony with accustomed usage for the nominal genus Labeceras Spath, 1925 (Class Cephalopoda, Order Ammonoidea)
Published in Opinions and declarations rendered by the International Commission on Zoological Nomenclature, in 1959, in volume 20, issue 23, pages 257-264
Date published:1959