SYNOPSIS OF GENERA. 
xxi 
Examples: Stictopora Gilberti, pi. xxvii, figs. 20-35; pi. xxviii, figs. 21, 22. 
Stictopora incisurata , pi. lx, figs. 1-18. 
Thamnotrypa, n. g. [Type, Thamnopora divaricata, Hall.] 
Zoarium consisting of a main branch or stipe, from which proceed lateral 
branches at nearly right angles to the main stem, celluliferous on both sides. 
Cells arising from a mesotheca. Apertures disposed in two ranges on the 
branches, and in three or sometimes four ranges on the main stipe. 
Example: Thamnotrypa divaricata , pi. xxxiii, figs. 9, 10. 
Taeniopora, Nicholson (Palaeontology of Ontario, p. 108. 1874). 
[Type, Taeniopora exigua, Nicholson.] 
Zoarium ramose, branches triangular or flattened, celluliferous on each face. 
Cells cylindrical, proceeding from laminae which radiate from the center to 
each angle of the branch, or from a simple mesotheca in the flattened branches. 
Intercellular tissue vesiculose. 
Example: Taeniopora exigua , pi. lxii, figs. 15-26. 
Prismopora, Hall (Trans. Albany Institute, vol. x, p. 158. 1881). 
[Type, Prismopora triquetra, Hall.] 
Zoarium ramose, consisting of triangular branches, frequently forming irreg¬ 
ular groups. Branches with the sides equal or unequal, concave ; celluliferous 
on each side. Cells tubular, arising from mesial plates which extend from the 
center of the branch to each angle. Intercellular tissue vesiculose. 
Examples: Prismopora triquetra , pi. xxviii, figs. 8-10; pi. xxix, figs. 9-15. 
Prismopora dilatata , pi. lxii, figs. 13, 14, 
Scalaripora, Hall (Tran. Albany Institute, vol. x, p. 159. 1881). 
[Type, Scalaripora scalariformis, Hall.] 
Zoarium consisting of groups of triangular prismatic branches, celluliferous 
on each face. Sides of branches concave and crossed by transverse, elevated, 
celluliferous scalse. Cells tubular, arising from the radiating mesothecse of the 
branches and from the inesothecse of the scalse. Margins of branches and 
scalse non-celluliferous. 
Examples: Scalaripora scalariformis, pi. xxix, figs. 4-8. 
Scalaripora subconcava, pi. xxix, figs. 1-3. 
