24 

 PLATE 8. Foraminiferce. 



FIG. i. .' Crystellaria. Succession of chambers; shell unequal sided, but com- 

 pletely formed the last formed whorl scarcely visible. These shells 

 were in great numbers and sizes, and very perfect. This shell is 

 evidently of vitreous formation, having a glassy transparency, and the 

 perforations distinctly seen on the surface. 



FIG. l. Nonionina. This is an equal-sided shell, resembling Nautilus 



Spirula, of twelve chambers, very beautifully and regularly formed. 



FIG. l. Coccospheres, of one, four, and nine chambers, quite transparent, and 



FIG. 2. appear like thin discs of glass, of unequal diameters, placed one on the 



other the margin of one being seen quite distinctly through the other. 



