PLATE XIV. 



(All titiure? mi this plate are forty times enlarged.) 



Page. 

 (toniatites OKEXisTRiA Phillips 68 



Figs. 1, 2. Prcitocoin'h. 

 Fig. 1 . From above. 

 Fig. 2. From front; diameter (1.46 iniii. 

 Figs. 3-5. Protoeonoh of same or a nearly related species from .Seott County, Ark. 

 Fig. 3. From above. 

 Fig. 4. From front. 

 Fig. 5. From side. 

 Figs. 6-8. Protoconcli with first two sutures. 

 Fig. 6. From above. 

 Fig. 7. From front. 

 Fig. 8. From side. 

 Figs. 9, 10. Larval stajje, diameter of 0.74 mm., protoconch and one-half of first whorl, 

 showing the first four sutures, from phylembryonic to the jiaranepionic substage. 

 Fig. 9. From side. 

 Fig. 10. From front. 

 Figs. 11, 12. Larval stage, diameter of 0.92 mm., first whorl, showing first eight sutures, 

 and transitions from the metanepionic (.iHarce.sto stage), through paranepionic (Paro- 

 rfoceras stage) to ananeanie { Prionoceras) stage. 

 Fig. 11. From front. 

 Fig. 12. From side. 

 Note. — This was Plate XIII, Proe. Cal. Acad. 8ci., .3d series. Geology, Vol. I. 



All specimens figured on this plate, except figs. 3, 4, 5, came from the Lower Carbonifer- 

 ous, St. Louis-Chester stage, Moorefield, Ark. 



171) 



