SYNOPSIS OF GENERA . 
xv 
Tropidopora, Hall (Report of State Geologist for 1886, advance sheets. 
Expl. pi. 25. 1886). [Type, Tropidopora nana, Hall.] 
Zoarium ramose, solid. Cell apertures arranged in irregular longitudinal 
rows, separated by sinuous ridges. Interior structure unknown. 
Example: Tropidopora nana, pi. xxv, figs. 25, 26. 
Diamesopora, Hall (Pal. N. Y., vol. ii, p. 158. 1852). 
[Type, Diamesopora dicliotoma, Hall.] 
Zoarium ramose, hollow, lined with an epitheca. Peristomes strongly ele¬ 
vated on the posterior margin. Intercellular space solid. 
Examples: Diamesopora constrida, pi. x, figs. 14-19 ; pi. xxiii a, fig. 7. 
Diamesopora camerata, pi. xxvi, figs. 9, 10. 
Acanthodema, Hall (Report of State Geologist for 1886, advance sheets. 
Expl. pi. 25. 1886). [Type, Trematopora alternata, Hall.] 
Zoarium ramose, solid. Cells arising from a filiform axis; apertures arranged 
in longitudinal rows separated by ridges. Usually with one or two nodes lon¬ 
gitudinally between the cells, which are represented in the interior by short tubuli. 
Examples: Acanthodema alternaium, pi. xxv, figs. 8-10. 
Acanthodema scutulatum, pi. lv, figs. 15-17; pi. lvi, figs. 19, 20. 
Bactropora, n. g. [Type, Trematopora? granistriata, Hall.] 
Zoarium with distant, bifurcations, solid. Base tapering, acute at the apex, 
striated. Cells tubular, arising from the center of the branch, septate. Aper¬ 
tures arranged in longitudinal rows. 
Examples: Badropora granistriata, pi. lxvi, figs. 20-22. 
Badropora curvata, pi. lxvi, figs. 14-16. 
Nemataxis, Hall (Report of State Geologist for 1886, advance sheets. Expl. 
pi. 25. 1886). [Type, Nemataxis fibrosus, Hall.] 
Zoarium ramose, solid. Cells arising from a filiform axis, in contact for the 
greater portion of their length, but separated by a fibrous tissue near the surface. 
Apertures arranged in longitudinal rows, separated by ridges. 
Examples: Nemataxis fibrosus, pi. xxv, figs. 30-36. 
Nemataxis simplex, pi. lxvi, figs. 17-19. 
Callopora, Hall (Pal. N. Y., vol. ii, p. 144. 1852). 
[Type, Callopora elegantula, Hall.] 
Zoarium ramose solid. Cells cylindrical, septate. Apertures circular or oval, 
often closed by a perforate operculum, marked by radiating ridges. Meso- 
