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An Encrinurus multisegmentatus species-group is defined. The main diagnostic criterion is the arrangement of the tubercles on the cranidium; a system of notation is used to indicate the positions of the main glabellar tubercles. E. multisegmentatus (Portlock) from the Killey Bridge Beds, Tyrone, is redescribed, and the Middle and Upper Ordovician species which constitute the group are discussed. One new species, E. lamonti from the Lower Drummuck Group, Ayrshire, is established.

• Read more about The trilobite Encrinurus multisegmentatus (Portlock) and allied Middle and Upper Ordovician species

Topotype Ordovician material containing Girvanella problematica Nicholson and Etheridge has been studied, several species being found to occur together. The genus is redefined and the limits of variation of the type species indicated.

• Read more about The type-species of the genus Girvanella (calcareous algae)

The well-known brachiopod genus Rhynchonella was erected by Fischer de Waldheim in 1809. It was founded on a new species R. loxia from the Upper Jurassic of the Moscow region. On the basis of topotype material, this species is here revised and redescribed with details of internal structures not previously studied. Other species which may belong to Rhynchonella s.s. are also discussed.

• Read more about The true Rhynchonella

Goniatites warslowensis sp. nov. and Pronorites ludfordi sp. nov. are described from the Bollandian (P1C Zone) of North Staffordshire.

• Read more about Upper Viséan goniatites from the Manifold valley, North Staffordshire