Platjb 10. 



Hemiphragma gldbrum, new species. 



Fig. 1. Nearly complete zoarium, natural size. 



Wassalem beds (D3), Uxnorm, Esthonia. 



Hemiphragma subsphericum, new Bpecies. 



2. Surface, X8, of one of tlie specimens of text fig. 179, showing the thin-walled 



apertures with semidiaphragms exposed. 

 Wesenberg limestone (E), Wesenberg, Esthonia. 



Batostoma michwitzi, new species. 



3. Nearly complete zoarium, one-half natural size. 



4. A complete, Tinbranched, small zoarium, two-thirds natural size. 



5. Branching fragment, two-thirds natural size. 



6. Surface of original of preceding, X8. 



Wassalem beds (D3), Uxnorm, Esthonia. 



Dianulites petropolitana Dybowski. 



7. Surface, X8, of the typical form of the species. 



Orthoceras limestone (B3), Reval, Esthonia. 



8. Epithecated, basal side of a specimen of the form hexaporites, natural size. 



9. Celluliferous face of a specimen of the same form, slightly enlarged, in which 



the hexagonal outline is produced by covered mesopores opening on a plane 

 with the ordinary zocecia. 



10. Surface of the same specimen still further enlarged. 



Glauconite limestone (B2), Tswos, on the Wolchow River, government 

 of St. Petersburg. 



11. Svurface of a specimen, natural size, showing hexagonal areas present in one 



portion and absent in the rest of the figure. 



Glauconite limestone (B2), Granaja Scheldicha, government of St. 

 Petersburg. 



368 



I 



