UPPER HELDERBERG GROUP. 
DESCRIPTIONS OF SPECIES. 
Trematopora (Trematella) annulata. 
PLATE XXV, FIGS. 22, 23 ; and PLATE XXVI, FIGS. 1, 2. 
Trematopora annulata. Hall. Trans. Albany Institute, vol. x, abstract, p. 5. 1881. 
“ “ “ Report of State Geologist for 18S2. Expl. pi. 24, figs. 1, 2. 1883. 
Trematella “ “ Report of State Geologist for 1885, advance sheets. Expl. pi. 25, figs. 22, 
23. 1886. 
Zoarium ramose, solid; branches from 2 to 3 mm. in diameter; bifurcations 
occurring at intervals of from 4 to 15 mm. Cells tubular, arising from the 
center of the branch and regularly curving to the surface; in contact for the 
greater portion of their length; diverging and leaving a short intercellular 
space as they approach the surface; septate, septa closely disposed. Cell 
apertures polygonal, diameter .25 mm.; irregularly disposed, usually in contact, 
frequently with small spinules at the angles. Pseudopores small, infrequent. 
Monticules elongate, transverse to the branch; two or more are usually in 
the same line giving to the branch an annulated appearance. There is a 
narrow space along the middle of each monticule usually destitute of cell 
apertures, but frequently with small pits or pseudopores. 
Formation and locality. Upper Helderberg group, Falls of the Ohio river. 
Trematopora (Trematella) arborea. 
PLATE XXV, FIGS. 16-21. 
Trematopora arborea, Hall. Trans. Albany Institute, vol. x, abstract, p. 5. 1881. 
Trematella “ “ Report_of State Geologist for 1885, advance sheets. Expl.pl. 25, figs. 16-21. 
1886." 
Zoarium ramose, solid; branches from 2 to 3 mm. in diameter; bifurcations 
occurring at intervals of from 2 to 7 mm. Cells tubular, polygonal, gradu- 
