PLATE 31. 
Fig. 1. 500. 3. Pentamerus ovalis. (Pag. 103.) 
1. A small valve, having a width slightly greater than the length. 
1 a. A larger valve, having a length nearly once and a half the width. 
Fig. 2. 
446. 
21. Lept^na obscura? 
(Pag. 103.) 
Fig. 3. 
# 
501. 
1. Platyostoma. 
(Pag. 103.) 
3 a. A large specimen of this species, having a portion of the last volution broken off. 
3 6. A smaller specimen, with the expanded portion of the last volution broken off. 
Fig. 4. 502. 31. Orthoceras clavatum. ( Pag. 104.) 
4 a. A fragment near the smaller extremity of the shell. 
4 6. A smaller fragment preserving a portion of the outer chamber. 
Fig. 5 a, b. 
503. 
1. Homalonotus delphinocephaeus. 
(Pag. 104.) 
Fig. 6. 
504. 
Fragment of Ichthyodorulite. 
(Pag. 104.) 
Fig. 7. 
Fragment of the rib of some vertebrate animal ? 
(Pag. 105.) 
