PLATE IX. 



Fig. 1. — A fragment of limestone from the " Bamosa-Banke " of Schulz, 

 Middle Devonian, Hebborn, Paffrath district, natural size. The rock is almost 

 wholly composed of the broken stems of Amphipora ramosa, Phill., sp., some being 

 covered with a thin imperforate membrane, while others have a vermiculate or 

 tuberculated exterior. 



Fig. 2. — Longitudinal section of a stem of Amphipora ramosa, Phill., sp., 

 enlarged 12 times, showing the axial tube and the large marginal vesicles, with 

 the intermediate reticulated tissue. Hebborn. 



Fig. 3. — Transverse section of the same, similarly enlarged. 



Fig. 4. — Longitudinal section of another specimen of the same, from the same 

 locality, enlarged 8 times. In this specimen marginal vesicles are not developed, 

 and the axial canal is intersected by well-developed tabula?. 



Fig. 5. — Part of the longitudinal section of the coenosteum of the recent 

 Distichopora coccinea, Gray, taken in the plane of the zooidal tubes, showing the 

 coenenchymal canal-system, enlarged 12 times. 



Fig. 6. — Portion of a mass of Idiostroma Boemeri, n. sp., from the Devonian 

 Limestone of Hebborn (Paffrath district), of the natural size. 



Fig. 7. — Transverse section of one of the cylindrical stems of the same, 

 enlarged twice, showing the axial tube and the tabulate zooidal tubes. 



Fig. 8. — Longitudinal section of the same, enlarged twice, showing the axial 

 tube with its funnel-shaped tabula? and its lateral branches. The section traverses 

 a second smaller longitudinal tube running parallel with the main one. 



Fig. 9. — Part of the surface of the same, enlarged, showing the vermiculate 

 ridges and the apertures of the zooidal tubes. 



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



Fig. 11. — Part of the outer zone of a transverse section of the same, enlarged 

 12 times, showing the tabulate zooidal tubes. 



