PlOB. 



PLATE XL. 



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. 



