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In Chazyan dolomitized biohermal reef complexes the bryozoans Atactotoechus chazyensis sp. nov. and A. kayi sp. nov. range throughout the standard Chazyan Series in the type section in north-eastern New York State and also occur on Isle La Motte, Vt. These primitive species of Atactotoechus considerably extend the geologic range of this genus (hitherto regarded as Devonian and early Carboniferous?) downward into middle Ordovician strata.Jordanopora gen. nov. appears to be a primitive representative of the leptotrypellids and the single species, J. heroensis sp.

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The impunctate, spire-bearing family Eospiriferidae contains the subfamilies Eospiriferinae and Cyrtiinae. The Eospiriferinae appear in the Upper Llandovery and persist until the Eifelian; whereas the Cyrtiinae appear in the Upper Llandovery and persist with certainty until the close of the Ludlow, but there is a single specimen from beds of Emsian age in Czechoslovakia. The family is characterized by the possession of radial filar ornamentation externally combined with a spiriferoid form.

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Dispersed microspores recovered from the Culm succession (Lower Carboniferous) of Spitsberge are described in detail and an assessment is made of their value in the elucidation of problems of stratigraphies correlation. The majority of the samples studied are from the Billefjorden Sandstones (i.e. the Culm sequence c Central Vestspitsbergen), which consist typically of sandstones, together with subordinate carbonaceous shale and siltstones and minor coal seams.

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Sections of four Lower Carboniferous dispersed-spore species, Labiadensites fimbriatus (Waltz) Hacquebard and Bares, Cristatisporites echinatus Playford, Camptozonotriletes velatus (Waltz) Playford, and Spinozonatriletes uncatus Hacquebard, are discussed and illustrated.

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Dispersed microspores recovered from the Culm succession (Lower Carboniferous) of Spitsberge are described in detail and an assessment is made of their value in the elucidation of problems of stratigraphies correlation. The majority of the samples studied are from the Billefjorden Sandstones (i.e. the Culm sequence c Central Vestspitsbergen), which consist typically of sandstones, together with subordinate carbonaceous shale and siltstones and minor coal seams.

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In the Barremian of North Bulgaria are found some new ammonite genera and species; Phyllopa-chyceras bontshevi sp. nov. occurs in the Upper Barremian, Costidiscus recticostatus Zone. Pseudothurmannia karakaschi sp. nov. and Holcodiscus caseyi sp. nov. are found in the Lower Barremian. Eoleptoceras (Tzankovi-ceras) tzankovigen. et sp. nov., Eoleptoceras (Wrightites) wrighti gen. et sp. nov., E. (W.) parvulum kraptshen-ensis gen. and subsp. nov., and Hemibaculites zaharievae sp. nov. occur in the Lower Barremian of Northwestern Bulgaria, in the Crioceratites emericianus Zone. Eoleptoceras gen.

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Fenestella rigidula M'Coy 1850 and F. lineata Shrubsole 1880 are considered to be conspecific. Their zooecial chambers are shown to contain structures comparable with the diaphragms of the Trepostomata, and a new genus, Archaeofewstella, is erected to contain them. One new species and two new subspecies are described: Archaeofenestella rigidula polynodosa, Fenestella pseudosubantiqua, and F. pseudosubantiqua catrionae. Elias's (1956) suggestion of the presence, in the English Wenlockian, of d'Orbigny's genus Reteporina from the Devonian is confirmed.

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Assemblages of organic-shelled microplankton from the Ampthill Clay (Upper Jurassic) of South Yorkshire are described. They comprise twenty-one species of dinoflagellates, of which two are new; twenty-seven species of hystrichospheres, of which three are new; and four species of presumed microplankton incertae sedis. From comparison With microplankton assemblages previously described, a stratigraphic position is tentatively assigned to the horizons studied.

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Diplograpids (seven species and nine subspecies) are described from various localities in the Lower Silurian of Great Britain, ranging in age from the zone of Monograptus cypftus to that of M. turriculatus. The study centres about Glyptograptus tamariscus (the genotype). From the time of its origin in the zone of M. cyphus, G. tamariscus displays considerable diversification along a number of different evolutionary lines. Other diplograptids which have some general similarity to G. tamariscus are also described, but they appear to be unrelated to it.

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The lectotype pygidium of Encrinurus punctatus (Wahlenberg), the type species, is from the Wenlock Series of the Island of Gotland, in which two allied species of Encrinurus are present; pygidia are not diagnostic but the size of the lectotype indicates that it should be attributed to the species with larger-sized individuals. An E. punctatus species-group is defined; conformity with the basic arrangement of tubercles on cranidium and pygidium is a necessary, but not sufficient, criterion of inclusion. The group includes also the following species: E.

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