PLATE XCIV-ConUnued. 



Panenka ABRUPTA. 

 Page 423. 

 See Plate 69. 

 Fig. 16. The left side of a specimen with the valves slightly displaced. 

 Hamilton group. Near Cumberland, Md. 



Panenka equilatera. 



Pago 4J9. 

 See Plate 69. 

 Fig. 17. The left side of a specimen showing the form and surface markings. 

 Hamilton group. DdpM, N. Y. 



Panenka multiraoiata. 



Page 417. 

 See Plate 69. 

 Fig. 18. The right side of the specimea described. 



Comiferous limestone. Clarence BoUow, Erie Co., N. Y. 



Pararca PR^CEDENS. 



Page 429. 

 Fig. 19. An imperfect left valve as obtained fi-om a gutta-percha impre&sion of a natural mould. 

 Comiferous limestone. Cayuga, CaiMda West. 



Pararca ereota. 



Page 432. 

 See Plate 70. 

 Pig. 20. A left valve showing the foi-m and surface markings. A profile of this valve is represented at the 

 right of the figure. 



Waverly group. Warren, Pa. 

 Fig. 21. The hinge of a right valve showing the minute crenulations. 

 Waverly group. Warren, Pa. 



Pararca venusta. 



Page 4.11. 

 Kg. 22. A right valve. 



Chemxmg group. Warren, Pa. 



Cardiola FLU0TDAN8, Banaiide. 

 See Plate 70. 

 Fig. 23. A right valve showing the fonn and surface ornamentations. Introduced for comparison with the 

 species of Panbnka, Pararca and allied forms. 

 Silurian. Bohemia. 



LUNULIOARDIUM TRANSVERSUM. 

 Page 439. 

 Fig. 24. Cardinal view of the specimen described, showing the hiatus along the cai-dinal line. 



Chemung group. Elmira, N. Y. 

 Pig. 25. The left side of the preceding. 



