NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
829 
Fig. 275.- — Genus Tretocycloecia Cam], 1919. 
A-I. Tretocycloecia ( Heteropora ) dicliotoma Reuss, 1847. A. Zoarium, natural size. B. 
Surface, X 25, showing ovicell pierced by the tubes with accompanying mesopores. C. Interior 
of the ovicell, X 25. D. Surface of specimen, X 12, showing ovicell covered by a new layer of 
tubes and made visible by fracture. E. Another example, X 12, showing the interior of the ovi- 
cell. F. Tangential thin section, X 25. G. Surface of zoarium, X 15. H. Vertical thin section, 
X 25. I. Transverse thin section, X 25. 
Helvetian of Doue la Fontaine (Maine et Loire) and Mus (Gard), France. 
