PLATE XL. 



FIGS. 



1-6. Placocista spinosa (Carter) Leidy. (p. 43) Fig. 1. 

 Broad view, x 300. -Figs. 2-4. Broad, narrow, 

 and vertical views, x 300. Figs. 5, 6. Outlines 

 of tests showing extremes of variation of form from 

 the normal, x 150. 

 7-9. P. jurassica Penard. (p. 46) Broad, narrow, and 



oral views, x 500. 

 10. P. lens Penard. (p. 47) Broad view, x 500. 



