A revision of North America genera of Ceramoporoid bryozoans (Ectoprocta): part II; Crepipora, Ceramoporella, Acanthoceramoporella and Ceramophylla

The Late Ordovician and Silurian genus Ceramopora Hall and the Silurian genus Favositella Etheridge & Foord are redefined and, together with the new Ordovician genus Papillalunaria, are included in the family Ceramoporidae. The Silurian genus Haplotrypa Bassler is tentatively retained in the family. Dnestropora Astrova is placed into synonymy with Favositella. Zoaria of Ceramopora imbricata Hall can have a basal lamina throughout or a celluliferous base near the margin of the zoarium or nearly throughout the zoarium. Laminations in the cell walls suggest that soft tissue occupied the under surface of at least part of the colony. It is not known if modified polypides occupied the tubes or cells, or if they are a kind of colonial interzooecial space that is similar to alveoli in lichenoporoid cyclostomes. The presence or absence of a celluliferous base may not be a character of taxonomic significance but may be dependent upon the size and nature of the substrate