PLATE XIV. 



Fig. I. Portion of a vertical section of MonticuUpora {Diplotrypa) IVhiteavesii, 

 Nich., from the Trenton Limestone of Peterboro', Ontario, enlarged twenty 

 times, showing the closely-tabulate small corallites, and the twofold con- 

 stitution of the tabulee of the large corallites. 



Fig. 2. Part of a tangential section of MoiticuHpora [Monotfypa) JJ'interi, 

 Nich., from the Devonian Limestone of Gerolstein in the Eifel, enlarged 

 twenty times, showing the thin-walled polygonal corallites, with an occa- 

 sional young tube intercalated. 



Fig. 2 a. Part of a. vertical section of the same, showing the thin walls, and the 

 uniform development of the tabulae of all the corallites. 



Fig. .3. A medium -sized specimen of MonticuUpora {Monoirypa) nndidata, 

 Nich., from the Hudson River Group of Toronto, Ontario, of the natural 

 size. The specimen is broken on one side. 



Fig. 3 a. Part of a tangential section of the same, enlarged twenty times, show- 

 ing the thin-walled, and nearly equal-sized corallites. 



Fig. 3 b. Part of a vertical section of the same, enlarged twenty times, show- 

 ing the thin and undulated wallSj and the uniform development of the 

 remote tabulae. 



Fig. 4. Part of a tangential section of MonticuUpora {MoJiotrypa) undulata, 

 Nich., from the Trenton Limestone of Peterboro', Ontario, enlarged 

 twenty times. 



Fig. 4 a. Part of a vertical section of the same, enlarged twenty times, showing 

 the thin undulated walls, and the remote tabulae placed at corresponding 

 levels. 



Fig. 5. One of the star-like elevations of tlie surface of ConstcUaria aiitheloidca. 

 Hall, from the Cincinnati Group of Ohio, enlarged. 



Fig. 5 a. Part of a tangential section of the same, taken just below the surface, 

 enlarged twenty times. The upper part of the portion figured traverses 

 one of the stellate areas or " maculae," while the lower part cuts across a 

 portion of the general surface. 



Fig. 5 b. Part of a vertical section of the same, showing the two sets of coral- 

 lites, enlarged twenty times. 



Fig. 6. Part of a tangential section of a typical example of MonticuUpora pul- 

 chella, E. and H., from the Wenlock Limestone of Dudley, enlarged 

 twenty times. The section cuts across one of the clusters of large 

 corallites. 



Fig. 6 a. Small portion of a longitudinal section of the same specimen, show- 

 ing the characters of the corallites just before they open on the surface, 

 enlarged twenty times. 



