PLATE III. 



Fig. I. A fragment of Mouticulipora {Heterotrypa) tiimida, Phill., from the Car- 

 boniferous rocks of Redesdale, Northumberland, of the natural size. 

 Fig. I a. Part of the surface of the same, enlarged eighteen times. 

 Fig. I b. Another part of the same specimen, showing a group of small coral- 



lites, similarly enlarged. 

 Fig. I c. A calice of the same, enlarged fifty times, showing the blunt spines 



round the margin. 

 Fig. I d. Tangential section of the same, enlarged eighteen times, showing the 



thick walls of the corallites, and the numerous hollow spines (spiniform 



corallites). 

 Fig. I e. Vertical section of the same, enlarged eighteen times. 

 Fig I f. Vertical section of a single corallite of the same, close to its mouth, 



enlarged fifty times, showing the peculiar structure of the wall. In the 



wall on the right-hand side is seen one of the hollow spines. 

 Fig. 2. Fragment of Mouticulipora tumida, Phill., var. miliaria, Nich., from the 



Carboniferous rocks of Redesdale, Northumberland, of the natural size. 

 Fig. 2 a. Part of the surface of the same, enlarged eighteen times, showing the 



numerous interstitial tubes. 

 Fig. 2 b. Part of a tangential section of the same, enlarged eighteen times. 

 Fig. 2 c. Part of the preceding section, enlarged fifty times. 

 Fig. 3. A specimen of Mouticulipora {Hcterotrypa) O'Nealli, James, from the 



Cincinnati group of Ohio, of the natural size. 

 Fig. 3 a. Part of the surface of the same, where the calices are open, enlarged 



fifteen times. 

 Fig. 3 b. Part of the surface of another specimen where the larger calices are 



closed by opercula, enlarged fifteen times. 

 Fig. 3 c. Part of a tangential section of the same, enlarged eighteen times, 



showing the large and small corallites. 

 Fig. 3 d. Small portion of the preceding section, enlarged fifty times, showing 



the structure of the wall. 

 Fig. 3 e. Part of the axial region of a transverse section of the same, enlarged 



eighteen times, showing the thin walls and angular form of the corallites. 

 Fig. 3/ Part of a vertical section of the same, enlarged eighteen times. 

 Fig. 4. Fragment of the shell of Strophonieua alteruata, Conrad, with a small 



colony o{ Mouticulipora [Ferotiopora) (?) Ortoni, Nich., growing upon it, of 



the natural size. From the Cincinnati group of Ohio. 

 Fig. 4 a. Portion of the surface of the same, enlarged fifty times, showing the 



peculiar form of the calices, and the rounded tubercles surrounding them. 

 Fig. 4 /'. Part of a tangential section of the same, enlarged sixty times, showing 



the peculiar shape of the corallites and their incomplete tabula, together 



with the numerous hollow spines (spiniform corallites). 

 Fig. 4 c. Vertical section of the same, embracing the entire thickness of the 



colony, enlarged eighteen times. 

 Fig. 4 d. Part of an oblique tangential section, cutting the tubes longitudinally. 



enlarged eighteen times. 



