PLATE IV. 



Halysites catenularia, var. Quebecensis (page 69). 



Figure 1. A few meshes, showing the general arrangement of the corallites, of a large 

 specimen from Lake St. John, Que., two miles south of Blue 

 Point. Natural size. 



Figure la. Transverse section of two corallites of the same. Five times the natural size. 



Figure 16. Longitudinal section of the same, showing the tabulae in the corallites and 

 tubules. Enlarged five times. 



Halysites catenularia, var. nitida (page 71). 



Figure 2. The shape of the meshes in a portion of a specimen from L'Anse a la Barbe, 



Baie des Chaleurs, Que. Natural size. 

 Figure 2a. Transverse section of corallites and tubules of the same, showing their 



relative size Enlarged five times. 

 Figure 26. Longitudinal section of the same showing the tabulae and septal spines. 



Enlarged five times. 



Halysites catenularia, var. simplex (page 70). 



Transverse section of two corallites of a specimen from near the mouth of 

 the Little Cascapedia River, Que. Five times the natural size. 

 3a. Longitudinal section of the same. Enlarged five times. 



Halysites catenularia, var. amplitubulata (page 71). 



Figure 3 

 Figure 



Figure 



4. Transverse section of two corallites and a tubule of a specimen from L'Anse 

 au Gascon, Baie des Chaleurs, Que., showing the great develop- 

 ment of the latter. Enlarged five times. 

 Figure 4a. Longitudinal section of the same showing the tabulae of the corallties and 

 tubule. Enlarged five times. 



Halysites compacta, Rominger (page 71). 



Figure 5. General arrangement of the corallites as seen in a specimen from the 



north end of Lake Temiscaming, Que., showing the triangular 



interspaces. Twice the natural size. 

 Figure 5a. Longitudinal section of two corallites and a tubule of the same ; the section 



does not lie exactly in the plane of the tubule, and shows an 



interspace on either side. Enlarged five times. 

 Figure 6. Portion of a specimen, from the same locality as the above, with nearly 



circular corallites and comparatively large interspaces. Twice 



the natural size. 

 Figure 7. View of the weathered surface of a specimen from the north-east side of 



the Columbia River, B.C. Natural size. 

 Figure 8. Arrangement of the corallites, tubules and interspaces in a specimen from 



the Isle of Mann (Burnt Island), Lake Temiscaming, Que. 



Twice the natural size. 

 Figure 8a. The same enlarged ; five times the natural size. 



