PLATE LXVIII. 



PAGE. 

 Fig. 1. WOBTHENOPOKA SPINOSA Ulr 669 



1. Several branches, natural size, as they lay upon a Blab. 



Keokuk group, Bentonsport, Iowa. 



Illinois State Museum. 

 1 a. A very perfect fragment of the natural size. 



Warsaw beds, Warsaw. 111. 



Illinois State Museum. 

 1 h. Portion of 1 a, x9, showing arrangement of zooecia and the spinose 



margins. 



1 e. Portion of same, x28. 

 1 d. Deep tangential section, x28. 



1 e. Half of a transverse section, x28; taken from a young example. 

 1 /. Transverse section of an old example in which the exterior of the 



zooecia is much thickened by laminated deposits, x2. 



1 g. Vertical section. X28. This probably belongs to the next species. 



Fig. 2. WOKTHENOPOBA 8PATUI/ATA PrOUt 870 



2 and 2 a. Fragment of the natural size, and a portion, x28. 



Warsaw beds. Warsaw. Ill 

 E. O. Ulrich's collection. 



Fig. 3. CTOLOPOBA FUNGIA Prout 671 



3. Surface of a specimen from Nauvoo, 111., x9. 



E. O. Ulrich's collection. 

 S a. Portion of fig. 3, x!8. This figure should be turned so that the right 



side is above. In this specimen the interspaces are oblong-quadrate. 



3 b. Another portion of flg. :!. x!8, showing part of one of the ma ulae. 



3 c. Tangential section, x28, showing structure and form of zocecia at differ- 

 ent levels, the lower portion being nearest the surface. 

 Warsaw beds, Warsaw, 111. 



3 d and 3 e. Two portions of another tangential section, x28 and 50, In which 

 the walls are transversely lined and the interspaces of different form 

 than in figs. 3 and 3 a. 

 Warsaw beds. 



3/. Vertical section, x28, showing the zocecia of a specimen of medium 

 thickness throughout their length. 



.3 (7. Very small upper portion of a vertical section, x28, showing more 

 numerous stages in the mesopores. 



