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Ammonites of the genus Acanthoceras from the Cenomanian of Rouen, France

Although Acanthoceras only forms a minority of the ammoniteifrom the Craie de Rouen, the locality is important as being the type locality of Acanthoceras rhotomagense, the type species of the genus and the most oft-quoted species. This study shows that almost all the Acanthoceras from Rouen can be regarded as one variable species which can be conveniently divided into five varieties, only one of which, A. rhotomagense var. clava-tum, is new. A. rhotomagense is a widespread species and marks an horizon low in the Middle Cenomanian. Acanthoceras basseae sp. nov., also from Rouen, is a rarity.

Calcareous algae new to the British Carboniferous

The first British records of two Lower Carboniferous algal taxa known from the U.S.S.R. and elsewhere are given: Ungdarella deceanglorum sp. nov., representing the Ungdarellaceae, an eatinct red algal family; and Exvotarisella maponi gen. et. sp. nov., representing the tribe Bereselleae of the family Dasycladaceae (green algae). U. deceanglorum is from the Visean of Wales, probably lower D2 Zone: E. maponi comes from the D2 Zone of Northumberland. Exvotarisella is considered to be structurally the most advanced genus of the Bereselleae.

Fertile Rhyniophytina from the Lower Devonian of Britain

A new genus Steganotheca is erected to include plants from the Downtonian of South Wales with naked dichotomously branching axes and terminal sporangia, which are longer than wide, sharply truncated apically, and with tapering bases. Comparison is made with other members of the Rhyniophytina (Banks 1968). Sterile Silurian axes probably belonging to the same genus are briefly mentioned.

The shell structure, mineralogy and relationships of the Chamacea (Bivalvia)

The superfamily Chamacea is a group which has constantly confused systematists concerning its relationship with other bivalves. Various authors have related it to the Cardiacea, Veneracea, Crassatellacea, Lucinacea, and the rudists (Hippuritacea).Most classifications have placed the Chamacea with the rudists; Newell (1965) placing them into the Hippuritoida, a relationship which Yonge (1967) considers beyond doubt.

The skull of Fabrosaurus australis, a Triassic ornithischian dinosaur

The skull of Fabrosaurus australis is described in detail. This study is based upon previously undescribed specimens from the late Triassic Red Beds of Lesotho.The presence of a predentary bone at the mandibular symphysis substantiates Ginsburg's concept (1964) of Fabrosaurus as a member of the order Ornithischia—though there is no evidence for any close relationship between Fabrosaurus and the Liassic Scelidosaurus.

The chelonian Rhinochelys Seeley from the Upper Cretaceous of England and France

The Cretaceous chelonian genus Rhinochelys Seeley 1869, which is based on skull material, has been reinvestigated. The foundations for Lydekker's original specific descriptions are shown to be inadequate and new diagnostic features for the genus and species are established. Only three British species are recognized: the type species R. pulchriceps (Owen 1851), R. elegans Lydekker 1889, and R. cantabrigiensis Lydekker 1889. R. amaberti Moret 1935 from La Fauge Valley, near Grenoble, France, is compared with the British species. A general description of the skulls and mandibles is given.
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