CORALS AND BRYOZOA. 
81 
terior margin of peristomes strongly elevated, oblique. Surface marked by 
slightly elevated monticules, the centers of which are distant from each other 
about 5 mm.; the apertures on these are of the same size and have the 
same direction as the others. Intercellular space vesiculose. 
This species may be distinguished by the large, oval, sub-imbricating cell 
apertures having the same general direction, and not interrupted by the 
monticules. 
Formation and locality. Upper Helderberg group, Falls of the Ohio river. 
Lichenalia conulata. 
PLATE XXXI, FIGS. 10-14. 
Liclienalla conulata. Hall. Trans. Albany Institute, vol. x, abstract, p. 9. 1881. 
“ " “ Rejiort of State Geologist[for 1885. Expl. pi. 31, tigs. 10-14. 18S7. 
Zoarium ramose, hollow; diameter of frond 15 mm.; thickness from 2 to 
5 mm. Cells tubular, at right angles to the surface ; septa strong, frequent. 
Apertures circular, papilliform, diameter of opening .20 mm., including 
margins .33 mm.; irregularly disposed, generally in contact: peristomes 
strong, converging- posterior portion the most prominent. Monticules conical, 
height 1.50 mm., centers distant from each other 5 mm., bases in contact. 
Cell apertures at center of monticules ovoid. Intercellular space near base 
irregularly vesicular, above regularly septate. 
This species can be readily distinguished by the papilliform cell apertures, 
and prominent conical monticules. 
Formation and locality. Upper Helderberg group, Falls of the Ohio river. 
Lichenalia subcava. 
PLATE XXVI, FIGS. 23-25. 
Lichenalia subcava, Hall. Trans. Albany Institute, vol. x, abstract, p. 8. 1881. 
“ “ “ Report of State Geologist for 1882. Expl. pi. 24, figs. 23-25. 1883. 
Zoarium lamellate. Cells at right angles to the surface. Apertures sub- 
triangular, diameter .20 mm., irregularly disposed. Anterior margin obso- 
