Genera of the Xorth American Palaeozoic Bryozoa. 549 



Fig. 116. Sceptropora facuJa, a. Segment of the average size and appearance; &, A vertical section, 

 showing tubular cells, and central axis; c, Transverse section of a lower half of a segment;- 

 d. Transverse section of the expanded portion of a very large segment. All xl8. 



Family Rhomboporidae, nov. fam. 



Zoarium ramose solid; apertures more or less regularly 

 arranged, oval or circular, placed at the bottom of a sloping 

 area, rhombic or hexagonal in outline, or between straight or 

 flexuous longitudinal ridges ; mesopores wanting. 



The following genera are included in this family: Ccelooonus, 

 KaoMBOPOEA and Tbematella. 



CcELOcoNus, Ulrich. 

 (Geol. Sur. 111., Yol. YIII, p. 402. 1890.) 

 Type, Coeloconus rhomhicus^ Ulrich. 

 " Zoarium simple, hollow, expanded gradually from the stri- 



Fio. 117. Coeloconus granosus, natural size and xl8. 

 Fig. 118. C. rhombicus, natural size and xl8. 



