FOSSILS OF THE CHESTER GROUP. 559 



GEXUS PTEROTOCRIXUS, L. and C. 

 PTEROTOCRLXUS DEPRESSUS, L. and 1 



PL 21, Fig. 13. 

 Pterotoerinus deprettu*. LTOX and CASSEDAY, 1860. Amer. Jour. Sci., new series, VoL 29, p. 68. 



Position and locality Chester division of Lower Carboniferous, Kas- 

 kaskia, Illinois. 



GEXUS GKAPHIOCRIXUS. 



GRAPHIOCRI^rCS DACTYLU8, Hall. 



PI. 20, Fig. 9. 

 Graphiocrinut daetylut, HAIX, 1860. (JeoL of Iowa, Supp. to Vol. I, p. 81. 



Locality and position St. Louis Limestone, Monroe county, 111. 



