PLATE I. 



Page. 

 Terebratella Vanuxemi Lyell and Forbes - „. 14 



Fig. 1. Dorsal view of a specimen avMcIi is rather coarsely plicated. 



2. Profile view of the same. 



3. View, enlarged one and a half diameters, of a finely plicated form. 



4. A ventral valve showing bifurcating i>lications. 



Terebratella plicata Say 12 



Fig. 5. Dorsal view of a large individual. 



6. Profile view of the same. 



7. Ventral view of a different individual of large size. 



8. Enlargement of the hinge portion of the last one to show the form of the foramen 



and plates. 



9. Enlarged view of a dorsal valve showing the loop and its connection. 

 Terebratulina Atlantica Morton 9 



Fig. 10. Dorsal view of a cast showing very fine striae and a flattened dorsal valve. 



11. Copy of Conrad's figure of T. glossa. 



12. Profile of a smaller crushed specimen. 



13. Dorsal view of a specimen from Farmingdale, N. J. 



Terebratulina lachryma Morton 12 



Fig. 14. Enlarged dorsal view of a specimen from Charleston, S. C, introduced for com- 

 parison with the last. 



Terebratula Harlani var. fragilis Morton 7 



Fig. 15. Dorsal view of a cast of a young shell showing the strong i)lications at this age. 



16. Profile view of the same. 



17. Dorsal view of a specimen of the normal form. 



IR. Dorsal view of a partial cast showing an extremely narrow form. 



Terebratula Harlani var. perovalis Morton 8 



Fig. 19. Dorsal view of a half-grown shell of T. Harlani possessing the features ascribed 

 to this variety. 



Terebratula Harlani Morton 3 



Figs. 20-22. Three views of a full-grown specimen from near Ncav Egypt, N. J., showing 

 the absence of plications which are sometimes very distinct in as large ones 

 as this. 

 23. View of the interior of the dorsal valve with the loop attached. The figure is 

 restored from several specimens, but not exaggerated. 



270 



