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Two new species of Clavagnostus, C. milli and C. burnsi, are described from the late Middle and early Upper Cambrian sequences of Tasmania. A third new species, Clavagnostus(?) rawlingi is questionably assigned to Clavagnostus. The genus Clavagnostus is reviewed. It is shown that the known species of Clavagnostus can be placed into three groups: (1) the C. repandus group which is characterized by a rounded glabellar front, no preglabellar median furrow, and a blunt pygidial axis which reaches the posterior border; (2) the C.

• Read more about The trilobite Clavagnostus Howell from the Cambrian of Tasmania

Opipeuter inconnivus gen. et sp. nov. is described. It is included with Cremastoglottus Whittard in a new family, the Opipeuteridae, which is probably closest to the Remopleurididae. It is also possible that Opipeuter is related to the enigmatic trilobite Bohemilla Barrande. The functional morphology of Opipeuter indicates a pelagic mode of life.

• Read more about A new pelagic trilobite from the Ordovician of Spitsbergen, Ireland, and Utah

The Llandeilo age of the Gorran Quartzites of south Cornwall and the Armorican affinities of the faunas suggested by some earlier authors are confirmed by a study of existing collections and material from two new localities. Revised descriptions and illustrations are given for species of Neseuretus and Kloucekia found in the quartzites of Veryan Bay and Gorran Haven. The presence of a species of Bathycheilus is recorded from there, with additional trinucleid and ogygiocaridinid material.

• Read more about Trilobites from the Gorran Quartzites, Ordovician of south Cornwall

Two new species of Hystichokolpoma (Pyrrhophyta) are described from the Aquia Formation (Upper Paleocene) of Virginia and Maryland. H. tumescens is characterized by a large, bulbous antapical process, and H. mentitum by a main body which in size, general appearance, and outlines of process bases resembles specimens of Eisenackia. With its delicate processes removed, H. mentitum is believed to masquerade as Eisenackia.

• Read more about Two new Paleocene dinoflagellates from Virginia and Maryland

In a study of part of Hall's type material, lectotypes are proposed for Climacograptus bicornis (Hall) and Climacograptus spiniferus Ruedemann. The variation in the proximal end of the latter is amply illustrated and discussed; it is also suggested that the latter may betIhe slightly modified descendant of the former. Climacograptus parvus Hall ( C.

• Read more about A revision of some Ordovician graptolites of eastern North America

The taxonomic status of the genera Priscogalea Deunff and Cymatiogalea Deunff is examined in the light of new evidence and the genera are emended. Six new species, two belonging to Priscogalea and four to Cymatiogalea, are described from the Shineton Shales (Tremadoc) of Shropshire, England.

• Read more about The Lower Palaeozoic acritarchs Priscogalea and Cymatiogalea

Previous literature on the microstructure and composition of the trilobite cuticle is reviewed. The micro-structure of the cuticle of Asaphus raniceps Dalman sensu Angelin (1854) is described in detail, and a table outlining the major features of the cuticles of fourteen other trilobite species is included. In Asaphus raniceps and some other species, two main regions of the cuticle are consistently present: an outer layer characterized by perpendicular prisms, representing about one-fifteenth of the total thickness of the cuticle and an inner area forming the bulk of the cuticle.

• Read more about Trilobite cuticle microstructure and composition

Transmission electron microscopy of fossil spores presents special difficulties. A major problem in megaspores is obtaining low power pictures of whole spores; this is overcome by using single-hole discs instead of grids. Care is needed to avoid damaging sporoderm ultrastructure by oxidation during preparation. Results achieved since 1965 are reviewed, and the sporoderm fine structures of Setosisporites (Carboniferous) as well as Salvinia and Alnus (both Tertiary) are illustrated and interpreted.

• Read more about Transmission electron microscopy of fossil spores

The Rochester Formation yields an acritarch microflora containing 24 genera and 46 species and varieties. Genus Hemideunffia; Species Domasia canadensis, D. rochesterensis, Hemideunffia trifurcata, Elektoriskos simplex, Filisphaeridium bifurcatum, Gorgonisphaeridium wenlockium, Lophosphaeridium rugosum and L. microgranulosum; varieties: Deunffia furcata var. niagarensis, D. monospinosa var. tonowandensis, and D. ramusculosa var.

• Read more about Acritarchs of the Middle Silurian Rochester Formation of southern Ontario

Present knowledge of agglutinated wall structure and composition is briefly reviewed. Examination of 19 recent species shows the existence of three wall types: simple imperforate wall with an organic cement; complex alveolar imperforate wall with an organic cement; 'perforate' wall with a calcareous cement. It is concluded that more attention should be paid to wall structure and composition in descriptions of species and in taxonomy. Forms with a calcareous cement seem to be stenohaline marine or hypersaline and therefore useful indicators of environment.

• Read more about Wall structure of some agglutinated Foraminiferida