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. riG8. 10-U. 



Lichenalia conulata. Hall. Trans. Albany Institute, vol. x, abstract, p. 9. 1881. 



Report of State Geologist for 1885. Expl. pi. 31, figs. 10-14. 1887. 



ZoABiUM 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 l.oO 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. 



LiCHENALU 8UBCAVA. 



PLATE XXVI, FIGS. 28-46. 



LieberuUia tttbcava,'llAhL. Trans. Albany Institute, vol. x, abstract, p. 8. 1881. 



Report of State Geolo^st for 1882. Expl. pi. 24, figs. 23-25. 1883. 



ZoABiUM lamellate. Cells at right angles to the surface. Apertures sub- 

 triangular, diameter .20 mm., irregularly disposed. Anterior margin obso- 



