PLATE II. 



Fig. 1. — Labechia ohioensis, n. sp. ; vertical section, enlarged 12 times. Cin- 

 cinnati group, Waynesville, Ohio. 



Fig. 2. — Tangential section, similarly enlarged. In this specimen the cavities 

 of the skeleton have been filled with opaque calcareous mud, and the skeleton has 

 been subsequently dissolved out, and replaced by transparent calcite. 



Fig. 3.— Labechia canadensis, Nich. and Mur. sp. ; vertical section enlarged 

 2^ times. Trenton Limestone, Peterboro', Ontario. The skeleton has been 

 "replaced " by calcite, so that the rows of dark oblong masses represent the dense 

 matrix filling the chambers, and the clear spaces of the drawing represent the 

 original skeletal framework. 



Fig. 4. — Another vertical section of the same, enlarged 12 times. 



Fig. 5. — The same drawn as if it had been preserved in the usual way, *. e. 

 having the chambers of the ccenosteum filled with transparent calcite, and the 

 skeletal framework opaque. 



Fig. 6. — Parallelopora ostiolata, Barg. ; tangential section, enlarged 48 times. 

 Devonian, Biichel (Paffrath district). 



Fig. 7. — Vertical section of the same, similarly enlarged. The sections show 

 the reticulate skeleton-fibre, traversed by numerous minute, dark, rod-like bodies, 

 which appear to be really tubuli injected with some opaque material. t t, tabulate 

 zooidal tubes. 



Fig. 8. — Clathrodictyon regulare, Rosen; vertical section, enlarged 24 times. 

 The concentric laminas show a delicate median line. Wenlock Limestone, Dudley. 



Fig. 9. — Stromatoporella eifeliensis, Nich. (?) ; tangential section, enlarged 12 

 times, showing the irregular zooidal tubes {t t) transversely divided. Devonian, 

 Teignmouth. 



Fig. 10. — Vertical section of the same, similarly enlarged. The irregular 

 zooidal tubes are here seen to be crossed by tabulse, and to extend from one inter- 

 laminar space to the next above, or to the one above that. 



Fig. 11. — Actinostroma clathratum, Nich.; surface enlarged about 12 times. 

 Devonian, Hebborn (Paffrath district). 



Fig. 12. — Clathrodictyon regulare, Rosen ; surface enlarged about 12 times. 

 Wenlock Limestone, Dudley. 



Fig. 13. — Clathrodictyon fastigiatum, n. sp. ; surface enlarged about 12 times. 

 Wenlock Limestone, Dormington. 



Fig. 14. — 8tromatoporella sp. (? S. curiosa, Barg.). A broken fragment of the 

 natural size, having the surface covered with a smooth and apparently imperforate 

 calcareous membrane. Middle Devonian, Biichel (Paffrath district). 



