PLATE III. 

 Haltsites catenularia, L. (page 68). 



Figure 1. Portion of an average specimen from Lake Temiscaming, Que., with 



oorallites of average size. Natural size. 

 Figure la. Transverse section of two eorallites of the same, showing the poeition of 



the tubules. Enlarged five times. 

 Figure lb. Oorallites and tubules of the same, as seen in longitudinal section. The 



tabulie of the tubules are strongly arched whilst those of the 



eorallites are generally flat or sli'ghtly concave. Enlarged five 



times. 

 Figure 2. Portion of a specimen from the Niagara of Ontario with oorallites that are 



almost circular. Natural size. 

 Figure 2a. Transverse section of two oorallites of the same showing the septal spines 



and the tubules. A longitudinal section of these oorallites is 



similar to what is shown in fig. 16. Enlarged five times. 

 Figure 3. A natural longitudinal section or a specimen from the Guelph formation of 



Ontario. Natural size. 

 Figure 3a. Transverse section of the eorallites of the same. Natural size. 



Halysites catenularia, var. micropora, Whitfield (page 70). 



Figure 4. Portion of a specimen from the Niagara of western Ontario showing a 

 marked irregularity in the shape of the meshes. Natural size. 



Halysites catenularia, var. gracilis, Hall (page 69). 



Figure 5. The general form and arrangement of the eorallites as seen in a specimen 



from East Selkirk, Man. Natural size. 

 Figure 5a. Oorallites of the same, as seen in transverse section. Enlarged five times. 

 Figure 56. Oorallites of the same, viewed in longitudinal section. The septal spines 



on the sides of the eorallites appear as dots. Five times the 



natural size. 

 Figure 6. Portion of a specimen from Jack Head Island, Lake Winnipeg, in which 



the oorallites are large and more than usually angular. Natural 



size. 

 Figure 7. Part of a specimen from Ohurohill Harbour, Hudson Bay, with very small 



eorallites. Natural size. 



