PLATE 4. 



Fig. 1. 387. Ch^tetes ? (Pag. 7.) 



Fig. 2. 388. 12. Lingttla ctineata. { Pag. 8.) 



2 a. A specimen of large size, nearly destitute of a shell. 



2 6. A small fragment of sandstone, showing upon its surface three individuals of different size. 



2 c. A small individual, preserving the shell nearly entire. The tv70 last are associated with a small species 



of Cythbrina, fig. 8. 

 2 «. A small fragment from a slab of sandstone, where the Lingcl* have been drifted by the waves. From 



the beak of each one extends a small ridge of stone which accumulated here, protected by the shell 



during tlie receding of the wave. 



Fig. 4, 5. 389. 22. Ateypa oblata. (Pag. 9.) 



4 a. View of the ventral valve. 4 6. View of base. 4 c. Profile view. 



5. The dorsal or larger valve imbedded in sandstone, which covers the lower part of the shell. It is impossi- 

 ble to say positively that this is identical with the preceding; but the partially imbedded specimen 

 affords no positive characters to distinguish it. 



Fig. 6. 390. 23. Atrypa plicata. (Pag. 10.) 



Fig. 7. 395. 15. Muechisonia? conoidea. ( Pag. 13.) 



Fig. 8. 400. 2. Cytherina CYUNDEiCi ( Pag. 14.) 



