''Hemiphragma'' is an extinct genus of
Middle Ordovician bryozoa
Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic invertebrate animals, nearly all living in sedentary colonies. Typically about long, they have a special feeding structure called a l ...
n. It had branching colonies with thick-walled
zooecial apertures and lots of
acanthopores, but few
mesopores.
References
{{Taxonbar, from=Q38494358
Middle Ordovician
Prehistoric bryozoan genera