This volume attempts to give a complete, annotated bibliography of two groups of microfossils with organic shell walls, the dinoflagellates and the acritarchs. Although bibliographies of these groups are known to have been prepared for private use by commercial organisations and although partial bibliographies have been appended to papers treating with these micro-organisms, no complete bibliography has been published to date. In view of the considerable importance these microfossils are assuming in stratigraphy, such a bibliography is regarded by the authors as likely to prove a useful tool for the extension of geological knowledge.
Two principal groups of microfossils are dealt with, the dinoflagellates and the acritarchs. The former group comprises unicellular algae of marine and fresh waters, usually represented in the fossil state by cysts, ruptured or unruptured. The latter group is defined in Evitt (1963, p. 300-2) and in Downie, Evitt and Sarjeant (1963, p.7); it comprises unicellular, or apparently unicellular, microfossils of unknown or doubtful affinity. Both groups occur together in microscopic preparations; the attribution of certain genera to one or the other group is doubtful. For these reasons they are treated together. Certain genera considered by the authors to be attributable to a family of the Chlorophyceae, the Tasmanaceae (see Downie, Evitt and Sarjeant, 1963, p. 15) are also included, since they have for long been treated as acritarchs and are still so regarded by some authorities: however, references dealing wholly with Tasmanaceae are so distinguished.
The study of these micro-organisms commenced around 1836, when a