PLATE XI. 



Fig. 1. — Vertical section of Stromatoporella eifeliensis, n. sp., enlarged 24 times, showing the minute 

 tubuli occupying the axes of the pillars and concentric lamina?. Middle Devonian, G-erolstein. 



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

 branching tubuli in the substance of the skeleton-fibre. The section traverses part of an astrorhizal 

 system. 



Pig. 3. — Vertical section of Stromatoporella, sp., enlarged 50 times, showing the minute tabula- 

 tion of the skeleton-fibre. Middle Devonian, Gerolstein. This species is peculiar in having the inter- 

 laminar spaces crossed by innumerable vesicular tabulae. 



Kg. 4. — Tangential section of the same, similarly enlarged. 



Fig. 5. — Tangential section of Stachyodes verticillata, M'Coy, sp., enlarged 24 times, showing 

 the tubuli of the skeleton-fibre filled with opaque matter. Devonian, Teignmouth. 



Fig. 6. — Part of a tangential section of another specimen of the same, from the Middle Devonian 

 of Hebborn (Paffrath district), in which tbe tubuli of the skeleton-fibre are filled with transparent 

 calcite. Enlarged 24 times. 



Fig. 7. — Part of the tangential section of Idiostroma ? sp. (? = Stromatopora capitata, Goldf.), 

 enlarged 24 times, showing numerous dark rounded spots in the interior of the transparent skeleton- 

 fibre. Middle Devonian, Hebborn. 



Fig. 8. — Vertical section of the same, similarly enlarged, showing two radial pillars and the inter- 

 vening tabulate zooidal tubes. Dark rod-like tracts and lines are seen in the interior of the skeleton- 

 fibre. 



Fig. 9. — Part of a tangential section of the original specimen of Parallelopora Goldf ussi, Barg., 

 enlarged 24 times. The skeleton-fibre is in the main opaque, but exhibits in its interior numerous 

 clear round spots or vacuities filled with transparent calcite. Middle Devonian, Hand (Paffratli 

 district). 



Fig. 10. — Part of a tangential section of Stromatoporella (Diapora) laminata, Barg., enlarged 

 24 times, showing the porous skeleton-fibre. Middle Devonian, Biichel. 



Fig. 11. — Tangential section of Syringostroma ? ristigouchense, Spencer, sp., enlarged 12 times. 

 Upper Silurian, Ristigouche. (From a specimen presented to the writer by Professor Spencer.) 

 The section shows that the skeleton-fibre has the porous structure of that of the Stromatoporidce, 

 while the large radial pillars with their radiating connecting-processes are arranged as in the genus 

 Actinostroma. 



Fig. 12. — Vertical section of the same, similarly enlarged, showing the porous skeleton-fibre, the 

 large radial pillars, and the regularly-developed horizontal " arms." 



Fig. 13.- — Tangential section of the original specimen of Syringostroma densum, Nich., enlarged 

 twelve times, showing the porous structure of the skeleton-fibre and its generally reticulated character. 

 The cut ends of a number of large-sized radial pillars are also shown. Devonian (Corniferous Lime- 

 stone), Ohio. 



Fig. 14. — Vertical section of the same, similarly enlarged. 



Fig. 15. — A small fragment of Stromatopora concentriea, Goldf., from the Middle Devonian of 

 Gerolstein, of the natural size. The specimen, both as regards general structure and mode of preser- 

 vation, is absolutely identical with the original example of the species figured in the ' Petrefacta 

 Germanise.' 



Fig. 16. — Tangential section of the same, enlarged 12 times, showing the porous and reticulated 

 character of the skeletal tissue. 



Fig. 17. — Tangential section of another specimen of the same, in the " Caunopora-staXe." The 

 " Caunopiora-tubes, " are exceedingly minute and very regularly placed, but have all the characters of 

 the tubes of " Caunopora " generally. They are much smaller than the tubes of any known species of 

 Aulopora or Syringopora in the Devonian Series. 



Fig. 18. — Vertical section of the same, enlarged 12 times, showing the irregular, tabulate zooidal 

 tubes. The portion figured embraces the thickness of a single " latilamina." 



