Lamottopora duncanae n. gen. et n. sp. which appears to have affinities with Eridotrypa Ulrich occurs in a Chazyan dolomitized biohermal reef complex on central Isle La Motte, Vermont. On southern Isle La Motte an arthrostylid, Helopora? sp. A, is abundant in dolomitized reefs having large colonies of Atactotoechus and "Phylloporina." Thick cylindrical zoaria which display recrystallized walls and which occur in Chazyan strata near Chazy, New York, and on Isle La Motte are referred to Nicholsonella.