PLATE X. 



Fig. 1. — Stromatoporella laminata, Barg., sp. (= Diapora laminata, Barg.). 

 Tangential section, enlarged 12 times. Middle Devonian, Biichel (Paffrath district). 



Fig. 2. — Vertical section of the same, similarly enlarged. The funnel-shaped 

 tabulae of the " Caunopor a-tubes " are well shown. 



Fig. 3. — Part of the surface of an unworn specimen of the same, enlarged 3 

 times, showing the mouths of the " Caunopora-tubes" connected here and there 

 by horizontal stolons. Biichel. 



Fig. 4. — Part of the surface of another beautifully preserved example of the 

 same, from the same locality, enlarged 12 times, showing that the surface-tubercles 

 are perforated by circular apertures at their summits. 



Fig. 5. — Stromatopora bilcheliensis, Barg., sp. ; part of a dendroid example, of the 

 natural size, from the Middle Devonian of Biichel. This is the Caunopora bilcheli- 

 ensis of Bargatzky, and is not uncommon in the Devonian of both Britain and 

 Germany, occurring both with and without the " Caunopora-tubes," which are 

 present in the specimen figured. 



Fig. 6. — Tangential section of the same specimen, enlarged 12 times. 



Fig. 7. — Vertical section of the same specimen, similarly enlarged. 



Fig. 8. — Stromatopora Riipschii, Barg., sp. ; tangential section, enlarged 12 

 times. Middle Devonian, Biichel. This is the Caunopora Hiipschii of Bargatzky. 

 It occurs in the Middle Devonian of both Britain and Germany, sometimes with 

 and sometimes without the " Caunopora-tubes" which are present in the specimen 

 figured. 



Fig. 9. — Vertical section of the same specimen, enlarged 12 times. The 

 section cuts through one of the " Caunopora-tubes" with its funnel-shaped tabulae, 

 and also divides transversely two of the horizontal connecting-tubes belonging to 

 the same system. 



Fig. 10. — Small portion of a polished specimen of Stromatopora Beuthii, 

 Barg. (?), of the natural size, from the Devonian Limestone, Teignmouth. In this 

 specimen the " Caunopora-tubes " are of exceptionally large size. 



Fig. 11. — Tangential section of the preceding, enlarged 12 times. The specimen, 

 like many of those from South Devon, and particularly those found in the pebbles 

 of the Triassic conglomerates, has undergone much crystallisation and squeezing. 

 The " Caunopora-tubes," as is commonly the case, have their cavities largely 

 filled up with a deposit of light-coloured sclerenchyma. 



Fig. 12. — Vertical section of the same, enlarged 12 times. The minute 

 structure of the skeleton is considerably altered and distorted by crystallisation 

 and pressure. 



