Stropherdonta layers of Craghead shale as seen by Schuchett and Sufjer September 23, 1909 on the Lynder farm Craghead Creek about six miles North of Fulton, Missouri. See vol. 17 (1923) Mo Geology the G.f. S., M.T.(29) 1909 by Sufjer. Upper Craghead shales not studied about 8'6" thick Middle Craghead li = Criminal layer 1'8" " Lower Craghead shales 12'8" Zone 1 3.0" shells most common in highest 6 to 8 inches Zone 2 6" shells again common here (Lynder farm) Zone 3 24" Bryozoan layers. Stropherdonta most abundant here. Zone 4 at the base of these 24" sharply from common (navalis) but do not reach out miles Interval of 24" with no shells seen. (Dynder farm) Zone 5 Basal layers best seen on Davidson farm 1/2 miles S.W. About 5 feet thick Call away limestone. They history of these Stropherdonta begin in this limestone.