Plate 4. 



[After Dybowski.] 

 Monticulipora rugom Edwards and Haime. 



Fig. 1. Tangential section introduced for comparison. 



Upper Ordovician [Maysville], Cincinnati, Ohio. 



Monticulipora wesenbergiana, new species. 



2. Fragment of zoarium, natural size (Wesenberg). 

 2a. Another fragment, X 2/3 (Wait). 



26. Base of zoarium attached to foreign body, XI (Wesenberg). 

 2c, d, e. Different views of another basal part of a zoarium. 

 2/. Tangential section. 



2g. Tangential section through the basal part of a zoarium. 

 2h. Another tangential section. 



Zone 2 [E], Wesenberg and Wait. 



Monticulipora, sp. 



3. Tangential section. 

 3a. Same, more enlarged. 



Zone 2 [D], Wassalem. 



Trachypora porosa, new species [not a bryozoan]. 



4. Fragment of a colony, X3. | 

 4a. Surface, enlarged. 



Zone 8 [Silurian], Kaugatomo-pank, Ohhesare-pank. 



Monticulipora sedilis Eichwald, sp. 



5. Tangential section of a mature specimen. 

 5a. Vertical section. 



Zone 2 [E], Wesenberg. 



Labechia conferta Lonsdale, sp. [not a bryozoan]. 

 6a. Tangential and vertical sections. 



Silurian, Dudley, England. 

 7a. Tangential and vertical sections of Russian example. 



Silurian, Hoheneichen. 



Stellipora revalensis, new species. 



8. Portion of a zoarium, X2/3. 

 8a. Tangential section. 

 86. A^ertical section. 



Zone 1 [C], Reval. 



Stellipora constellata, new species. 



9. Tangential section. 

 9a. Vertical section. 



Zone 2 [?F], Hohenholm, 



356 



