700. NOTES ON LEWESICERAS AND NOWAKITES (PACHYDISCID AMMONITES) FROM THE CRETACEOUS OF HOKKAIDO : STUDIES OF THE CRETACEOUS AMMONITES FROM HOKKAIDO AND SAGHALIEN-XXXVI

Abstract

This is the first description of Lewesiceras and Nowakites from the Cretaceous of Hokkaido. It comprises four new species which are allied to L. rhodanicum (ROMAN and MAZELAN), L. elmii COLLIGNON, N. lemarchandi (DE GROSSOUVRE) and N. tallavignesi (D'ORBIGNY), respectively. The reasons why these two genera are rare in Hokkaido are discussed in connexion with the evolutionary history of the family.