PLATE LXXV. 



PAGE. 



Fig. 1. BATOSTOMELLA SPINULOSA Ulr 434 



1, 1 a and 1 l>. Three specimens of the natural size. 

 Chester group, Sloan's Valley, Ky. 

 E. O. Ulrich's collection. 



1 c. Surface x!8, showing the sunken interspaces, mesopores, and abund- 

 ant aeanthopores. 



1 d. Tangential section, x!8, showing structure of peripheral region of 

 zoarium. 



1 e and 1 /. Two vertical sections, x!8, one with, the other without dia- 



phragms. 



Fig. 2. BATOSTOMELLA ABKUPTA Ulr 435 



An example of this species, natural size. 

 Chester group, Sloan's Valley, Ky. 

 Illinois State Museum. 



2 a. Another specimen, natural size, from the same locality. 



E. 0. Ulrich's collection. 



2 6. Surface of tig. 2 a, slightly abraded, x!8. 

 2 c and 2 d. Well preserved fragment, natural size, with small portion of 



surface, x!8. 



Sloan's Valley, Ky. 



E. O. Ulrich's collection. 



2 e. Half of a vertical section, x!8, showing the abrupt thickening of the 



walls at the surface. 



Fig. 3. BATOSTOMELLA NITIDULA Ulr 436 



3. Fragment of the natural size. 



Chester, 111. 



Illinois State Museum. 



3 a. Surface of same, x!8. Over the lower hah* of the figure the zocecia 



apertures preserve the perforated diaphragms. 



3 l>. Tangential section, x!8, showing distribution of zooecia, mesopores, and 



aeanthopores. 



Fig. 4. BATOSTOMELLA INTEKSTINCTA Ulr 434 



4. Basal expansion with a number of branches broken away. Natural size. 



4 a. Surface of same, x!8, showing relative size of zooecia and interspaces 



on the explanate portion of the zoarium. 



4 b. Irregular branch, natural size. 



4 c. Surface of same, x!8, showing smaller zoooeia apertures and more nu- 

 merous mesopores than 4 a. 



4 d and 4 e. Tangential and vertical sections of a branch, x!8. 

 St. Louis group, Pella, Iowa. 

 Illinois State Museum. 



