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EXPLANATION OF PLATE VIL 



Fig. 1. Productus Prattenianus. (Pago 113.) 



a. Ventral view of a large example. 



6. Side view of an average-sized example. 



c. Posterior view of tbe same. 

 Fig. 2. Productus punctatds. (Page 114.) 



a. Ventral view of a typical example from Iowa. 



6. Dorsal view of the same. 



c. Lateral view of an example distorted by pressure. 

 Fig. 3. Syxocladia iuserialis. (Page 107.) 



a. Poi'tion from near tbe base of tbo polyzoary, natural size. 



1). Portion of anotber example, enlarged, showing pores (after Meek). 



c. Enlarged view of a specimen split through all the cells, showing them to be larger below 

 than they are at tbo apertures. 

 Fig. 4. PbLYPORA stragcla. (Page 108.) 



a. Fragment from near the base of the polyzoary, natural size. 



h. Portion of the same, enlarged, showing the pores. The rows of iiores as shown in the figure 

 aro too distinct vertically, and not enough so obliquely. 

 Fig. 5. Glauconome nereidis. (Pago 105.) 



a. Fragment of a polyzoary, a little enlarged. 



6. Part of the same, more enlarged. 



c. A portion, still more enlarged, showing the dimorphous pores. 



(Z. View of non-poriferous side, a little enlarged. 



c. Same, more enlarged. 



