I.—Trilobites from the confinis Flags (Ordovician) of the Girvan District, Ayrshire.

Abstract

Three new genera and seventeen new species of trilobites from the Flags with Valcourea confinis (Salter) of the Girvan District are described and named, and thirty-six species are figured. The genera constitute a normal Middle Ordovician assemblage for the Girvan District; none of the species is known elsewhere. There is a close resemblance to the fauna of the Lower Edinburg Formation of the Appalachian Valley of the U.S.A., and many of the generic stocks are known earlier only from the Chazy and Lincolnshire Formations of North America.