PLATE 31 B. 
Fig. 1. 145. 8. LeEpT£NA ALTERNISTRIATA. (Pag. 109.) 
1 a, Dorsal valve of a large specimen, showing a very regular alternation in the size of the striz. 
1 b. Ventral valve of the same specimen, the strie being regular and uniform in size. 
1c. A smaller specimen, presenting a greater extension of the cardinal extremities, and an irregular alterna- 
tion of the striz upon the surface. 
Bigs, 146. 9. LeprmNa SERICEA. (Pag. 110.) 
2 a, b. The form and surface of the shell are perfectly preserved in this specimen, both valves of which have 
distinct larger striz alternating with several smaller ones, 
2c, d. The opposite valves of another specimen, showing the equal striz and a few concentric lines of growth. 
2 e. Interior of the ventral valve, showing two winglike papillose callosities for the visceral attachment. 
2 f, shows a variation from the preceding internal structure. 
2g. Interior of the convex valve, showing the visceral impression, margined by a sharp elevated ridge. 
2h. View of the cardinal area of the convex valve, showing the deltoid aperture which is partially closed. 
Fig. 3. 147. 10. Leprana FILITEXTA. (Pag. 111.) 
3 a. Ventral valve of a large specimen. 3 b. Cardinal area. 3c. Interior of the dorsal valve. 
3 d. Dorsal valve of a smaller specimen. 3 e. Cardinal view of the same. 
3 f. An enlarged portion of the surface, showing the textile character. 
Fig. 4. 148. 11. Leprana PLANUMBONA. (Pag. 112.) 
4 a&b. Views of the two valves; the ventral one 6 showing some strong imbricating lines of growth. 
4 ec. Cardinal view, showing the nearly linear area and closed foramen. 
ad. Interior of the concave valve. 4 e. Lateral view of the shell. 
Fig. 5. 149. 12. Leprena DEFLECTA. (Pag. 113.) 
5 a. Dorsal valve of the specimen. 5 6. Cardinal area of the same. 
Fig. 6. 150. 13. Leprmena recta. (Pag. 113.) 
6 a. View of the ventral valve. 6 6, Cardinal view of the same shell. 
Fig. 7. 151. 14. Leprana PLANOCONVEXA. (Pag. 114.) 
7 a. View of the dorsal valve, with one of the cardinal extremities produced beyond the other. 
7b. A smaller specimen. 7c. Profile view of the shell. 7 d. Cardinal view of the first specimen. 
Fig. 8. 152. 15. LepraNa TENUILINEATA. (Pag. 115.) 
Fig. 9. 153. 16. Lepraena suBTENTA. (Pag. 115.) 
9 a. View of the dorsal valve. 9b. Interior of the hinge margin. 
Fig. 10. 154. 17. Leprana (Species undetermined ). (Pag. 116.) 
10 a. Ventral valve, showing the equal radiating strie. 10 6. Dorsal valve, with unequal striz. 
10 e. Cardinal area, and the same enlarged, showing the open foramen and imperforate beak. 
