Genera of the ]^orth American Palaeozoic Bryozoa. 589 



pits (mesopore apertures). The principal difference between this 

 genus and Trematopora is the presence of interapertural pits. 



Dekayella, Ulrich. 

 (Jour. Cin. Soc. Nat. Hist., Yol. Y, p. 155. 1882.) 

 Type, Dekayella ohscura^ Ulrich. 



Zoarium ramose, cells tubular, polygonal, arising from the 

 center of the branch and curving outward ; diaphragms distant ; 



181 



Fig. 177. Dekmjella prcenuntia. Natural size ,and surface, x9. 



Fig. its. Transverse sections of the same, xl8. 



Fig. 179. Vertical section, x9. 



Fig. ISO. D. obscura, surface, xlS. 



Fig. 181. Transverse section, x9. 



Fig. 182. Vertical section, x9. 



