PLATE LX. 



PAGE 



Fig. 1. POLYPORA BADIALIS Ulrioh 591 



1. Obverse surface, x9. 



1 a. Portion of same, x 25, showing some of the zocecia apertures entirely 



closed and others with the radial denticles. 

 1 6. Eeverso, x9. 

 1 c. Horizontal section, x!8. 



1 d. Deep tangential section, x!8, showing structure of basal layer. 



Keokuk group. Keokuk, Iowa. 



E. O. Ulrioh's collection. ' t 



Fig. 2. POLYPOBA VARSOVIENSIS PrOUt 593 



2. Perfect obverse surface, x9, showing relative size of branches andfenes- 



trules and distribution of zooecia apertures. Some of them preserve 

 the covers. 



2 a. Usual appearance of the obverse side, x9. 

 2 b. Reverse, x9. 



Warsaw bods, Warsaw, 111. 

 Illinois State Museum. 



Fig. 3. POLYPOBA SPININODATA Ulr 594 



Beverse, x9, showing the strong hollow nodes opposite the dissepi- 

 ments. 



Warsaw beds, Warsaw, 111. 

 Illinois State Museum. 



Fig. 4. POLYPORA BISERIATA Ulr 592 



4. Obverse surface, x9, showing opercula and relative size of branches and 



fenestrules. 



4 a. Obverse side of another example, x9, with zooecia apertures open. 



4 1>. Reverse. x9, showing the usual flattening of the branches before bifur- 

 cation. 



Warsaw limestone, Monroe Co., 111. 

 Illinois State Museum. 



Fig. 5. POLYPOKA COBTICOSA Ulr. (See also PI. LV, and LXI> 596 



5, 5 a, 5 6, 5 c. Four specimens, natural size. 



Chester group, Chester, III. 

 Illinois State Museum. 



