BRYOZOA—CYCLOSTOMATA, 



123 



XVIII. Anolotichia Ulrich. 

 Ramose or digitate zoaria of subpolygonal tubes with remote 

 diaphragms, lunarium elevated at surface, traversed by fine vertical 

 tabulated tubes. Mesopores few. Ordovicic. 



25. A. impolita (Ulrich). (Fig. 182,0.-) Ordovicic. 



Large, bushy, of frequently and irregularly divided solid 

 branches; large, moderately thin-walled zocecia, with hexagonal, 

 subrhomboidal apertures, practically of uniform size and with 

 well-developed lunarium. 



Stones River of Minnesota ; abundant and characteristic. 



9 



f f 



Fig. 182. a, Anolotichia impolita, surface and section, X 9 \ u > Ceramophylla fron- 

 dosa, X x /z and surface, X A*A '■> <"> Bythotrypa laxata, surface, X4-X anc * X 9 \ d, Fistu- 

 lipora carbonaria, tangential and longitudinal sections, X 9 '■> e > Chilotrypa hispida- 

 half of a vertical section with axial tube on right, and tangential section showing inter- 

 stitial vesicles, X 9 J /> Buskopora dentata, surface X A% an d X 9 '■> £"> Meekopora 

 clausa and section, X %- (All after Ulrich. ) 



XIX. Ceramophylla Ulrich. 

 Like Ceramoporella, but erect and bifoliate, the two layers grown 

 back to back. Ordovicic. 



26. C. frondosa Ulrich. (Fig. 182, b.) Ordovicic. 



Fronds 0.5 to 2.0 mm. in thickness; substellate maculae of meso- 

 pores at intervals of about 3 mm.; oblique apertures with posterior 

 margin well elevated, and 2 to 3 mesopores to each zocecium. 



Black River of Minnesota. 



XX. Bythotrypa Ulrich. 

 Massy or lamellate, with long zocecial tubes with thin dia- 

 phragms, subovate apertures and large lunaria. Numerous meso- 



