EXPLANATION OF PLATE IIL 



Fig. 1. PiiYLLOGiJAPTUS LoniNGi. (Pago 51.) 



a. Side view of stipe, uatiiral size. 



b. Portion of same, enlarged, sbowing shape of cell-apertures. 

 Fig. 2. Lingula ? manticula. (Page 52.) 



a. Dorsal valve. 

 h. Ventral valve. 

 Fig. 3. Aci;oti!i:ta pyxidicula. (Page 53.) 



a. Exterior view of ventral valve. 



b. Posterior view of tbe same. 



c. Side view of the same. 



d. Dorsal valve. — All vcrj- much enlarged. 

 Fig. 4. Stropiiomena fontinalis. (Page 54.) 



a. Dorsal valve. 



h. Veutral valve of another and smaller shell. 



c. Fragment of a, enlarged, showing bifurcation of striae and their fine crcnulation. 

 Fig. 5. Orthockras (Camaroceras) colon. (Page 56.) 



a, b, and c. Different lateral views. 



d. View of the convex side of a septum, showing shape, size, and position of the siphuncle. 

 Fig. 6. Bellerophon allegoeicds. (Page 55.) 



a. Side view, 

 ft. Dorsal view. 



e. Posterior view. 



Fig. 7. Leperditia bivia. (Page 58.) 

 a. Left valve. 

 1). Right valve. 



c. View of lower edge of left valve, showing the beveled border. 



d. View of lower edge of right valve, showing the position of the two pores. 

 Fig. 8. DlCELI.OCEPIIALUS ? FLAGRICAUDUS. (Page GO.) 



a. Natural size. 



b. The same, enlarged. 



Fig 9. Megalaspis belemnurus. (Page 59.) 



