PLATE 4. 
387. Ch.2btetes-? 
(Pag. 7.) 
Fig. 2. 388. 12. Lingula cuneata. (Pag. 8.) 
2 a. A specimen of large size, nearly destitute of a shell. 
2 b. 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 two last are associated with a small species 
of Cytherina, fig. 8. 
2 e. A small fragment from a slab of sandstone, where the Lingula: 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 the receding of the wave. 
Fig. 4, 5. 389. 22. Atrypa oblata. (Pag. 9.) 
4 a. Yiew of the ventral valve. 4 b. 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. 
390. 
23. 
Atrypa plicata. 
(Pag. 10.) 
395. 
15. 
Murchisonia? conoidea. 
(Pag. 13.) 
400. 
2. 
Cytherina cylindricu 
' '(Pag. 14.) 
