Abstract
Chitinozoans from samples of the Trenton, Utica, and Lorraine groups of the St. Lawrence Lowlands are described.The studied assemblages contain well-known upper Caradocian and Ashgillian species and also new species, such as Conochitina pygmaea and Hercochitina cristata.The stratigraphic and geographic distribution of the microfossils allows identification of taxa with stratigraphic value.The assemblages so characterized also allow a link to be made between younger assemblages from the Ashgillian sequence of Anticosti Island, previously described by the author, and older ones described by Martin from Caradocian beds of the St. Lawrence Lowlands.