PUTE 4 (bli). 



Fig. 1. 28. 1. Lept^na plicifera. (Pag. Id.) 



I a. Figure of the conYcx vaWe. 

 1 h. Cast of convox val%e, with a portion of the shell remaining : cast of visceral cavities magnifiei). 



Fig. 2. 29. 2. Leptjena incrassata. (Pag. 19.) 



•2 a, b. Convex valves of this species. 2 c. Ventral valves. 



•i d. Cast of the interior of the convex valve, and the same enlarged. 



Fig. 3. 30. 3. LeptjENa fasciata. (Pag- 20.) 



3 a, b. Convex valves of two individuals. 3 e. A larger specimen of the same. 



Fig. 4. 31. 1. Orthis costalis. (Pag. 20.) 



1 a. An imperibci shell, showing the radii towards the margin. 

 •I ft. A cast showing the visceral marking, and casts of radii near the base of the shell. 



4 c. .\n impression of the convex valve, smaller than the other specimens. Such impressions are abundant. 



Fig. 5. 32. 1. Atbypa dubu. (Pag. 21.) 



Fig. 6. 33. 2. Atbypa acutirostra. (Pag- 21.) 



The Uvo lower figures are of the natural size ; the upper one is enlarged. 



Fig. 7. 34. 3. Atrypa plena. (Pag- 21.) 



7 a. View of the ventral valve, showing the beak of the dorsal valve closely incurved over the beak of the 



former. 7 b. Lateral view of the same individual. 



7 e. Dorsal valve of a small specimen. 



7 d. Front view of a large specimen. 7 e. Dorsal valve of the same. 



Fig. 8. 35. 4. Atrypa plicifera. (Pag. 22.) 



8 a, ft. View of ventral valve, and front of same individual. 



5 e, d. Ventral valve and front view of another individual. 



Fig. 9. 36. 6. Atbypa altilis. (Pag. 23.) 



9 a. View of the ventral valve, showing the beak of the dorsal valve. 9 h. View of the dorsal valve. 

 9 c. I.ateral view of the same shell. 9 d. Front view, showing the elevation of the mesial radii. 



Orbicula? deformis. (Pag. 23.) 



Metoptoma? ddbia. (Pag. 23.) 



IlljENUs abcturus. (Pag. 23.) 



IlljEncs crassicahda? (Pag. 24.) 



AsAPHUs? OBTUsns. (Pag. 24.) 



ASAPHUS MABGINALIS. (Pag. 24.) 



Isotelus oigas? (Pag. 25.) 



IsOTELtrS CANALI8. (Pag. 25.) 



IS tL 19 Labrum or epistoma of an hoUltu, perhaps of /. canaHi. 



Fig. 20. 45. 1. Cebaubus? (Species Mwdrtcrwtwerf). (Pag. 26.) 



Fig. 21. A fragment of the crust of an unknown trilobite. 



