Collection 60ATb 178 consists of several blocks of limestone containing a profusion of moderately well preserved corals referable to a single species (probably new) of the genus Microplasma. The genus is given a Middle-Upper Silurian range in the Treatise, but Devonian species have been assigned to it also. I have checked the illustrations of most of the Devonian “Microplasmas” of which I have a record. In all cases the specimens are either obviously not of the genus or are atypical in form. The specimens at hand are typical, and very similar to the western European Silurian species.I have not been able to check all Devonian references to Microplasma and it is possible that the genus does range above the Silurian. However, the similarity of the Alaskan forms to the typical ones is strong evidence for Middle or Upper Silurian age for the collection.
Some of the limestone blocks contain poor brachiopods. These have been turned over to the proper specialist who will report further, only if the brachiopods can be identified and/or contribute information on the age of the specimens.