PLATE XIII. 



Crepidophyllum Archiaci, Billings (page 154). 



Figure 1. Longitudinal section of one of the corallites of a specimen from Thedford, 



Ont. ; twice the natural size. 

 Figure la. Transverse section of the same ; twice the natural size. 



Crepidophyllum colligatum, Billings (page 155). 



Figure 2. A few calyces of a specimen from the township of Walpole, Haldimand 



county, Ont. 

 Figure 2a. Longitudinal section of one of the corallites ; twice the natural size. 

 Figure 26. Transverse section of the same ; twice the natural size. The upper half of 



the section passes through one of the expansions of the corallite ; 



the lower half is through the cylindrical part. 



Diphyphyllum CyESPiTOSUM, Hall (page 158). 



Figure 3. Relative position of the corallites to each other as seen in transverse section ; 



from the type specimen of C. pelagicum from Becscie River Bay, 



Anticosti, Que. 

 figure 3a. A corallite of the same specimen, shown partly in longitudinal section ; 



twice the natural size. 

 Figure 36. Transverse section of the corallite ; twice the natural size. 



Diphyphyllum multicaulk, Hall (page 159). 



Figure 4. Side view of part of a specimen from Grand Manitoulin Island, Lake Huron. 



Figure 4a. Corallites, as seen from above, in the same specimen. 



Figure 46. Longitudinal section of one of the corallites ; twice the natural size. 



Figure 4c. Transverse section of the same ; similarly enlarged. 



Diphyphyllum Verneuilanum, Milne Edwards and Haime (page 159). 



Figure 5. Side view of corallites of a specimen from the township of Walpole, Haldi- 

 mand county, Ont. 



Figure 5a. Longitudinal section of a corallite showing the extension of the vesicular 

 structure into the connecting outgrowth ; twice the natural size. 



Figure 56. Transverse section of the same showing septa as well as vesicles in the out- 

 growth ; twice the natural size. 



Diphyphyllum Simcoense, Billings (page 161). 



Figure 6. A few of the corallites of the type specimen from near Woodstock, Ont. 

 Figure 6a. Longitudinal section of one of the corallites ; twice the natural size. 

 Figure 66. Transverse section of the same ; enlarged twice. 



