Contributions to the study of the comparative morphology of teeth and other relevant ichthyodorulites in living superaspecific taxa of Chondrichthyan fishes. Addendum to Part A, No. 1b: Hexanchiformes - Family: Chlamidoselachidae; No. 5: Order: Heterodontiformes - Family: Heterodontidae; No. 6: Order: Lamniformes - Families: Cetorhinidae, Megachasmidae; Addendum 1 to No. 3: Order: Squaliformes; Addendum 1 to No. 4: Order Orectolobiformes; General Glossary; Summary Part A. Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, Biologie, 63, 185–256
