PLATE 98. 
Page 
Fig. 1-8. Spikifer arenosus. 425 
1 & 2. Two views from the same specimen, which is slightly distorted and the shell partially 
removed. 
3. Ventral valve of a large specimen. 
4. A dorsal view, showing the area and foramen. 
5. View of a ventral valve. 
6. The dorsal side of a specimen where the shell is worn from the mesial fold, and partially 
from the sides of the valve. 
6 a, b. Front and profile views of the same specimen, the ventral side being a cast of the 
interior. 
7. The interior of a large ventral valve. 
8. Enlargement of the plications, showing fine concentric striae. 
Fig. 8 a , b . Cyrtia ro.strata. 429 
8 a, b. Ventral and cardinal view of an imperfect cast of this species. 
