530 



Report of the State Geologist. 



celluliferous on both faces • ^ * * zooecia with subcircu- 

 lar apertures ; interspaces apparently solid at the surface ; occu- 

 pied by vesicular tissue internally. As growth ^proceeded, a 

 gradually increasing deposit of minutely perforated calcareous 

 laminae covered the lower and older portions of the^zoarium." 

 (Meek and Worthen.) 



87 



Fig. 87. Evactinopora, illustrating various forms of this genus. 



Pachydiotya, Ulrich. 



1882.) 



(Jour. Cin. Soc. J^at. Hist., Yol. Y, p. 152. 



Type, Pachydictya rohusta, Ulrich 



" Zoaria varying from paralleled, margined, narrow branches, 

 to large undulating expansions. The edges are acute and have 

 a noncelluliferous border • * ^ ^ zooecia rising rather ab- 

 ruptly from the mesial lamina, near which they have very thin 

 walls ; are broad elliptical or subquadrate in outline, arranged in 

 longitudinal series, and partially separated from each other by 

 small vesicles. Toward the surface their walls are thickened, 



