Abstract

Eleven species of Middle and Upper Ordovician graptolites are described and illustrated, a lectotype is selected for Orthograptus reudemanni (Gurley) and the occurrence of eighteen other species is recorded. The specimens were collected from sections along the Bécancour, Nicolet, Nicolet Sud-Ouest, and St. François Rivers of the St. Lawrence Lowlands, Quebec. The graptolite zonal scheme proposed by Riva for eastern North America is reviewed and adopted in the present study.

You do not currently have access to this article.