8 ILLUSTRATIONS. 



Page. 



Plate XVII. Fig. 1, Goniatiteskentuckiensis Miller; &gB. 2-5, Goniatites neiosomi Smith; figs. 6-8, 



Gastrioceras illinoisense Miller and Gurley; figs. 9-11, Gastrioceras kansasense 



Miller and Gurley; figs. 12-14, Goniatites greencastknsis Miller and Gurley; figs. 



15-17, Giwlrioceras suhcavnm Miller and Gurley; figs. 18-20, Agankles jessiex 



Miller and Gurley 1S2 



XVIII. Glyphioceras calyx Phillips, development from early larval stage to maturity 184 



■ XIX. Figs. 1-2, Maensleroctms paralkhim Hall; figs. 3-8, Muensteroceras oweni Hall; figs. 

 9-11, ProlecanUes li/oni IMeek and Worthen; figs. 12-14, Agankles wlatorius de 



Konincli - 186 



XX. Figs. 1-8, Schwtoceras hyatti Smith; figs. 9-11, Gonioloboceras welleri Smith; figs. 



12-15, Dimorphoceras iexanum Smith 188 



XXI. Figs. 1-6, Gonioloboceras welleri Smith; figs. 7-9, Gastrioceras (/lobulosum Meek 

 and Worthen; figs. 10-13, Schistoceras hyalli Smith; figs. 14-16, Popanoceras 

 ganti Smith; figs. 17-19, Agathiceras ciscoense Smith; figs. 20-22, Schuclurtites 



grahami Smith 190 



XXII. Figs. 1-3, Medlicottia copei White; figs. 4-8, Waagenoceras aunmind White; figs. 



9-11, Popanoceras walcutii White 192 



XXIII. Prodromites gorbyi Miller 194 



^XXIV. Figs. 1-4, Prolecaniles gurleyi Smith; figs. 5-7, Aganides discoidalis Smith; figs. 



8-12, Muensteroceras osagense Swallow; figs. 13-20, Gastrioceras welleri Smith 196 



' XXV. Figs. 1 and 2, Prodromites gorbyi Miller; figs. 3 and 4, Prodromites prxmaturus ^ 

 Smith and Weller; fig. 5, Hedenstrwmia mojsisovicsi Diener; figs. 6-8 Prodromites 



ornatus Smith 198 



^XXVI. Figs. 1-5, Gon(a(i(es ermi's^n're Phillips; figs. 6-13, Goniatites striatus Sowerhy; figs. 



14-18, Goniatites subcircularis Miller 20C 



XXVII. Waagenoceras liilli Smith 202 



' XXVIII. Gastrioceras e.rcelsum Meek 204 



"■ XXIX. Gastrioceras excelsum Meek 206 



