588 



Report of the State Geologist. 



The following genera are included in this family : Batostoma, 

 Gallop OK A, Dekayella, Nichols onelli and Trematopoba. 



1882.) 



Batostoma, TJlrich. 

 (Jour. Gin. Soc. Nat. Hist., Yol. Y, p. 154. 

 Type, Batostoma implicatum^ Ulrich. 



Zoarium ramose ; cells tubular, arising from the center of the 

 branch and curving outward ; cell walls in the axial region very 

 thin, becoming thicker in the peripheral region ; cell apertures 

 circular ; peristomes equally elevated ; inter apertural surface 

 with numerous pits (mesopore apertures), occasionally there are 

 ornamental nodes or spines on the surface. . 



This genus in all probability is synonymous with Gallopoba. 



174 



175 



Fig. 173. Batostoma Minnesotense, zoarium, natural size. 



Fig. 174. B.Winchelli. Surface xl8. 



Figs. 175, 176. B. varium. Vertical section and transverse sections, x9. 



Gallopoba, Hall. 

 (Pal. K Y., Yol. II, p. 144. 1852.) 

 Type, Callojpora elegantula^ Hall. 



(Plate 18, figs. 1-7.) 

 Zoarium ramose, smooth or tuberculated ; cells cylindrical, aris- 

 ing f roni an imaginary axis, gradually curving to the surface ; 

 diaphragms few or numerous; intercellular space occupied by 

 tabulate mesopores ; tabulae very closely disposed, much more so 

 than in the cell tubes ; apertures circular ; when perfect, closed by 

 an operculum ; closely and irregularly disposed, frequently nearly 

 or quite in contact; interapertural space occupied by angular 



