Notes on the Structure of an Early Dictyonema.

Abstract

The more important points in connexion with the structure of D. flabelliforme are:—1. The absence of any real approach to the spiral arrangement of the thecae along the stipes.12. The absence of a common canal; and the consequent budding of each hydrotheca direct from the preceding one.13. The initial constriction of each hydrotheca cavity.4. The budding of the bithecae from the sides of the hydrothecae along which they lie.5. The early stage at which the presence of the bithecae is observed.6. The derivation, indifferently “right-handed” or “left-handed” of the crossing canal.7. The nature of the dissepiments—hollow bars derived principally as outgrowths of the bithecae.