Lower Devonian conodont stratigraphy is incomplete although several authors have recently contributed to its refinement. The Icriodus woschmidti woschmidti- and I. w. postwoschmidti-Faunas are Lower Gedinnian. Descendants of I. woschmidti are recorded from the higher Lower Gedinnian, which also yields some representatives of the Bischoff-Sannemann fauna. However, the latter, containing forms indicating upper Lower Gedinnian, Upper Gedinnian, and portions of the Siegenian, possibly comes from a concentrate horizon. Early subspecies of I. huddlei occur in the Siegenian and develop progressively in the Lower and Upper Emsian. I. bilatericrescens and Polygnathus appear first in the Emsian. P. linguiformis s.s. and the...