PLATE VII. 



Fig. 1. — Stromatopora discoidea, Lonsd. ; tangential section, enlarged 12 times. 

 Wenlock Limestone, Ironbridge. 



Fig. 2. — Vertical section of the same, similarly enlarged, showing the minute 

 tabulate zooidal tubes. A single latilamina alone is shown. 



Fig. 3. — Stromatoporella eifeliensis, n. sp. ; tangential section, enlarged 12 

 times, c c, astrorhizal canals crossed by " astrorhizal tabulae." 



Fig. 4. — Vertical section of the same, similarly enlarged, c c, Cut ends of the 

 astrorhizal canals, showing the astrorhizal tabulee. The general structure of the 

 skeleton in this form is very similar to that of 8. granulata, Nich., but it seems to 

 be sufficiently separated from the latter by the great development of the astrorhizal 

 system and by other minor characters. 



Fig. 5. Stromatoporella granulata, Nich. ; tangential section, enlarged 12 times. 

 Devonian (Hamilton Formation), Arkona, Ontario. 



Fig. 6. — Vertical section of the same, similarly enlarged. 



Fig. 7. — Stylodictyon columnar e, Nich. ; a fragment, of the natural size, 

 showing a vertical polished section. Devonian (Corniferous Limestone), Sandusky, 

 Ohio. 



Fig. 8. — Upper surface of the preceding specimen, of the natural size. 



Fig. 9.— Vertical section of the same, enlarged 5 times. 



Fig. 10. — Tangential section of the same, enlarged 12 times. The portion 

 figured exhibits the centre of an astrorhiza. 



Fig. 11. — Vertical section of the same, enlarged 12 times, embracing one of the 

 intervals between a pair of the vertical columns. 



Fig. 12.—Rosenella macrocystis, Nich ; vertical section enlarged 12 times. 

 Wenlock Limestone, Wisby, Gotland. [Coll. Dr. George J. Hinde.] 



Fig. 13. — Tangential section of the same, similarly enlarged. 



