Article: Upper Llandeilo trilobites from the Berwyn Hills, North Wales
Sixteen species in twelve genera are described including the following new species, Bumastus powis-ensis, Marrolithus magnificus, M. lirellatus, Atractopyge sedgwicki, A. williamsi, and Metopolichas contractus. The fauna was collected from three small inliers of Llandeilo rocks in the Berwyn Dome, North Wales. There is a large indigenous element in the fauna, and an exotic element, in which two species appear to be from the Appalachian province, and one might possibly be from the Bohemian province. Two species are at present cryptogenetic.