Article: Upper Llandovery trilobites from the Pentland Hills, Scotland

Well-preserved trilobites of Upper Llandovery age are reported from two of the three Silurian inliers in the Pentland Hills. In addition to two species of Phacopina previously described, there are some fifteen species belonging to Proetidae, Aulacopleuridae, Harpetidae, Cheiruridae, Encrinuridae, Calymenidae, Odontopleuridae, and Lichidae. In the older beds (Reservoir and Deerhope formations) trilobites are relatively rare and appear to be endemic to the Midland Valley of Scotland. In the succeeding lower part of the Wether Law Linn Formation the more abundant trilobites occur together with a rich brachiopod fauna and bear pronounced affinities with trilobites from the East Baltic. The hypostome of Acernaspis (Eskaspis) sufferta (Lament) is described for the first time. New taxa described are Cyphoproetus comitilis n. sp. and Harpidella (Harpidella) thomasi n. sp.