PLATE XII. 



Page 



Figs. 1, 2. Pronorites pk.epermicus Karpinsky (IohIk^vv the young stages) 44 



Fig. 1. First two sutures. 



Fig. •!. Embryo chamber. 

 F"iG. 3. Proxorites cyclolobus Philliii," 44 



Fig. 3. Sutures, twice enlarged. 

 Figs. 4-9. Par.\legocer.\s newsomi Smith sp. nov 101 



Lower Coal Measures, Morrillton, Ark. 



Fig. 4. Side view, partly restored. 



Fig. 5. Front view. 



Fig. 6. Side view of inner whorl taken out of the large specimen shown in fig. 1. 



Fig. 7. Front view. 



Fig. 8. Sutures taken from the inner whorl of 2.t mm. diameter. 



Fig. 9. Sutures on the outer whoil. 

 Fk;. 10. Glyphiocer.\s Di.\nEM.\ Goldfuss, showing develojmient of the sutures fi3 



a. First suture. 



h. Second suture. 

 r. Third suture. 



d. At 1.25 mm. diameter. 



e. At 2.25 mm. 

 /. Adult. 



Fm. 1 1 . T0RN0CERA.S RETRORsi ji von Biich 73 



II. First suture. 



b. Second suture. 



c. At 1.75 mm. diameter. 



d. At 2.50 mm. 



e. At 10 mm., adult. 



Figs. 12-15. Pronorites cyclolobis Phillips variety ark.vnsasex.sis Smith 43 



Lower Carboniferous, Chester stage. Pilot Mountain, Carroll County, Ark. 

 Fig. 12. Side view. 

 Fig. 13. Rear view. 

 Fig. 14. Front view. 

 Fig. 15. Sutures. 



Spec. Nat. Mus. 



Note. — Figs. 1-3 were part of PI. XXIII, Proc. Am. Philos. Soc, Vol. XXXV; figs. 1 and 2 are 

 after Karpinsky, Ammoneen der Artinsk-Stufe, PI. I, fig. 2, e, f, g; fig. 3 is after 

 Phillips, Geol. Yorkshire, Pt. II, PI. XX, fig. 42. 

 Figs. 4-11 were part of PI. XIX, Proc. Am. Philos. Soc, Vol. XXXV; fig. 10 is after 

 Branco, Palseontogra]ihica, Vol. XXVII, PI. IV, fig. 1; fig. 11 la after Branco, Pala^onto- 

 graphica. Vol. XXVII, PI. V, fig. 7. 

 Figs. 12-15 were part of PI. XXIV, Proc. Am. Philos. Soc, Vol. XXXV. 



172 



