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Recent studies of the acritarchs have shown that many have features in common with one or other of two major groups of planktonic algae—the prasinophyceae (tasmanitids) and the dinophyceae (dinoflagellates). However, studies of the ultrastructure, excystment mechanisms, and knowledge of their geographic and historical distribution are too incomplete at the moment to allow a worthwhile natural classification of the 300 or so acritarch genera.

• Read more about Observations on the nature of the acritarchs [The Fifteenth Annual Address, delivered March 1972]

The Miocene alga Neosolenopora armoricana sp. nov. is described. It is most exceptional amongst Soleno-poraceae in showing clear reproductive structures interpreted as similar to Corallinacean asexual sporangia, single and fused; a possible sexual structure is also described. This development came at the very end of solenoporacean evolution.

• Read more about A Miocene solenoporoid alga showing reproductive structures

The largest specimen of Praiaspongia hicksi Hinde yet found is described from the lop of the Upper lltay Dalradian succession in western Ireland. The age is uncertain but suggestive of Middle Cambrian (St. David's Series).

• Read more about A Protospongia from the Dalradian of Clare Island, Co. Mayo, Ireland

Coniferous tree stumps and roots attributable on evidence of wood anatomy to the form-genus Glypto-stroboxylon Conwentz occur in Upper Bartoniau (Upper Eocene) strata at two localities in the Hampshire Basin, southern England. They are the first trees found in growth position in the English Lower Tertiary. Evidence that they grew in a flooded or waterlogged habitat is given by the mode of fossilization and characteristics of the associated flora.

• Read more about In situ coniferous (taxodiaceous) tree remains in the Upper Eocene of southern England

The genus Cisternifera Walford 1894 is shown to be based on a misinterpretation of Mesenteripora wrighti Haime 1854, with a calcified terminal membrane.

• Read more about Exceptional preservation in cyclostome Bryozoa from the Middle Lias of Northamptonshire

Aptychi found in the body chambers of four specimens of Sonninia (Papilliceras) from Skye, western Scotland, are described and figured. The aptychi do not exactly fit the aperture but it was not possible to establish conclusively whether they functioned as opercula or as part of the jaw apparatus.

• Read more about The aptychi of Sonninia (Ammonitina) from the Bajocian of Scotland

The unique holotype of Crassigyrinus scoticus Watson is almost certainly from the Visean Gilmerton Ironstone of Scotland, as suggested by Watson. It consists only of the right side of a large primitive amphibian skull with a very long postorbital region. The pattern of dermal bones, which includes a well-developed preopercular, is intermediate in configuration between that of a rhipidistian fish and the earliest Amphibia, the ichthyostegids. Crassigyrinus may also have a rhipidistian-like course of the infraorbital lateral line system, but in the amphibian form of open sulci.

• Read more about On Crassigyrinus scoticus Watson, a primitive amphibian from the Lower Carboniferous of Scotland

An account is given of new, well-preserved, deep-bodied holostean fishes (family Semionotidae) from the continental Lower Jurassic, India. A new genus, Paradapedium, has been erected with Dapedium egertoni Sykes 1853 as type-species. New specimens are assigned to P. egertoni. The validity of Tetragonolepis oldhami Egerton 1878 is supported but T. analis and T. rugosus are found to be indeterminable. The age and distribution of deep-bodied semionotids is discussed. The evidence from the fossil fishes is in favour of a Liassic age for the Kota Formation.

• Read more about New specimens of Lower Jurassic holostean fishes from India

A sample of some 10 kg from the Strenuella Limestone (Lower Cambrian) of Comley, Shropshire, etched in 10% acetic acid, has produced over 1000 small fossils. These include 281 specimens of Lapworthella dentata Missarzhevsky. L. nigra Cobbold, already known from higher in the Comley succession, was not found in this sample. L. dentata typically occurs in the upper part of the Atdabanian Stage in Siberia.

• Read more about Lapworthellids from the Lower Cambrian Strenuella Limestone at Comley, Shropshire

The internal morphology of the European Middle Devonian brachiopods Bifida and Kayseria is truly athyridid in every character, especially with regard to the structure of the spiralia. Several previously unknown internal structures and two new species, Kayseria alvea, and K. nohnensis are described. One species of Kayseria is also shown to have an unusual external shell cover consisting of bushy frills located in rib troughs.

• Read more about Bifida and Kayseria (Brachiopoda) and their affinity