CORALS AND BRYOZOA. 
93 
Stictopora ovatipora. 
PLATE XXVII, FIGS. 12-19 ; AND PLATE XXVIII, FIGS. ‘23, 23a. 
Stictopora ovatipora, Hall. Trans. Albany Institute, vol. x, abstract, p. 14. 18S1. 
“ “ Report of State Geologist for 1882. Expl. pi. 25, figs. 23, 23 a. 1883. 
" Report of State Geologist for 18S5, advance sheets. Expl. pi. 27, figs. 12-19. 188(1. 
Zoarium consisting of a dicliotomously branching, flattened stipe ; transverse 
section broadly lenticular ; width of branches from 2 to 3 mm., margins 
essentially parallel; greatest thickness less than 1 mm. Cell apertures oval, 
length about .25 mm , width from one-half to two-thirds the length ; mar¬ 
ginal apertures larger than the others, and more nearly circular; disposed in 
longitudinal rows, increasing by interstitial addition. Rows separated by 
prominent ridges. Peristomes strong, distinctly and equally elevated, having 
two slight denticnlations, which are invariably situated on the outer margin 
of the aperture. Intercellular space irregularly vesicular. 
This species closely resembles S. Gilberti, but may be distinguished by its 
narrow branches with essentially parallel margins, which give to the frond a 
somewhat rigid appearance. 
Formation and locality. Upper Helderberg group, Falls of the Ohio river. 
Stictopora vermicula. 
PLATE XXVII, FIGS. 2-4. 
Stictopora vermicula, Hall. Report of State Geologist for 1885, advance sheets. Expl. pi. 27, figs. 2-4. 
1S86. 
Zoarhjm consisting of a dicliotomously branching and flattened stipe, of irregular 
appearance; transverse section sub-lenticular, abruptly narrowing and very 
thin near the margins; width of branches from 2.50 to 3 mm., margins 
slightly divergent; non-celluliferous space comparatively wide, flat; greatest 
thickness about .80 mm. ; bifurcations frequent. Cells tubular, length about 
.80 min., for a little more than one-half their length essentially parallel with 
the mesotheca, then abruptly turning outward. Cell apertures broadly oval 
or circular, frequently pustuliform, diameter from .25 to .30 mm., the mar¬ 
ginal ones larger than the others; disposed in indistinct longitudinal and 
