CORALS AND BRYOZOA. 21 



CALLOPORA, Hall. 1852. 

 Callopoka oppleta, n. sp. 



PLATE XI, FIGS. 2:!, 24. 



In part Callopnra inacropnra, Hai.l. Thii-ty-second Rept. N. Y. State Mus. Nat. Hist., p. 152. 1880. 

 " Callopom inacropora, " Report of State Geolog'ist for 1882. Expl. pi. 11, figs. 23-29. 1883. 



ZoARiUM ramo.se, .solid, diameter of branches 3 mm.; bifurcations frequent. 

 Cell apertures circular, diameter .33 mm., irregularly disposed, frequently in 

 contact: margins strong, equally elevated. Mesopores minute, not more than 

 one series between adjacent apertures. 



Formation and localily. Lower Helderberg group, near Clarksville, Albany 

 county, N. Y. 



Callopora cellulosa. 



I'LATK XII, FIGS 1-9; I'LATE XIII, FIG. 9; and PLATE XXHI A, FIG. 6. 



CalUtpora cMulosa, Hall. Thirty-second Rept. N. Y. State Mus. Nat. Hist., p. 154. 1879. 



Report of State Geologist for 1882. Expl. pi. 12, figs. 7-9 ; pi. 13, fig. 9. 1883. 



ZoARiUM ramose, solid, diameter of branches from 3 to 5 mm. ; bifurcations 

 frequent. Cells tubular, often sub-polygonal from mutual pressure ; arising 

 from the center of the branch, gradually diverging till within one mm. of the 

 surface, when they turn abruptly outward ; walls, except near the surface, 

 very thin. Septa thin, distant. Apertures circular or broadly oval, diameter 

 from .20 to .25 mm. ; irregularly disposed, frequently in contact: margins 

 strong, distinctly and equally elevated. Mesopores minute, angular: margins 

 of the same height as those of the apertures. Intercellular space septate for 

 a short distance below the surftice. 



The surface of this species is variable in appearance ; very frequently the 

 margins of the apertures and mesopores are smooth ; at other times the 

 margins of the apertures have comparatively strong nodes, the mesopores 

 being nearly or quite obscured ; in others the margins of both the apertures 

 and mesopores are ornamented with minute spines, which often are so 

 numerous a.s to entirely obscure all other features of the surface. 



