lambe.J CANADIAN PALEOZOIC CORALS. 43 



Calapgecia Canadensis, Billings. 



Plate I., figs. 6, 6a and 7. 



Oalapceeia Canadensis, Billings. 1865. Canadian Naturalist, new series, vol. II., p. 426. 

 CedapcBcia Huronmsis, Billings. 1865. Ibid, p. 426. 



Cal'ip't.cia Anticostiensis, Billings. 1865. Ibid, p. 426 ; and 1866, Cat. Sil. Foss. of 

 Anticosti, p. 32, figs. 15a, 166. 

 opora cribriformix, Nicholson. 1874. Geological Magazine, new series, vol. I., 

 p. 253, figs, la — c. 

 i< n Nicholson. 1875. Palaeon. of Ont., p. 25; and 1875, Geol. 



Survey of Ohio, vol. II., pt. II., p. 187, pL XXII., figs. 

 8, 8a, 86. 

 Houghtoniu Huronica, Rominger. 1876. Geol. Sur. Mich., Foss. Corals, p. 17, pi. III., 



figs. 3 and 4. 

 Columnopora cribriformis, Nicholson. 1879. Palseoz. Tab. Corals, p. 164, pi. VII., figs. 

 2, 2a-d. 



Whiteaves, 1880. Rep. of Progress for 1878-79, Geol. Survey 

 of Canada, p. 48 C. 



Whiteaves, 1881. Rep. of Progress for 1879-80, Geol. Survey 

 of Canada, p. 57 C. 



Corallum forming hemispherical, subspherical or somewhat turbinate, 

 at times irregularly rounded, masses of polygonal, subpolygonal or circular 

 corallites diverging from a basal beginning or point of attachment ; reach- 

 ing a height of nearly 6 inches with a breadth of about 4 inches. Corallites 

 usually nearly equal in size in the same specimen and varying in diameter 

 in different specimens from 2 to 4 mm. ; either in contact and polygonal, or 

 circular and separated from each other by a space of varying width. In 

 the same specimen circular and polygonal corallites with intermediate 

 gradations, sometimes occur, or they may be all circular or all polygonal, 

 the circular corallites being at times nearly their own diameter apart but 

 more frequently about half that distance and often almost in contact. 

 Walls of the corallites of moderate thickness, about -25 mm. through, 

 apparently completely amalgamated when the walls are in contact, per- 

 forated by large pores placed close together and forming regular hori- 

 zontal and longitudinal rows. Pores circular, oval or quadrangular and 

 so numerous &? to reduce the walls to a mere reticulation of upright 

 bars and horizontal rings the former of which are generally somewhat the 

 stronger of the two and appear in the inside of the corallites as longitu- 

 dinal ridges. Spiniform septa stout at the base, sharply pointed, about 

 •3 mm. long and inclined slightly upward, occurring in from about 

 eighteen to twenty-two longitudinal rows, a spine springing from each 

 intersection of the mural ridges with the transverse rings. Tabulae com- 

 plete, horizontal, sometimes slightly concave or convex, often somewhat 

 irregular from the introduction of secondary tabulae ; from four to six in 

 a space of 2 mm. When the corallites are not in contact the interven- 



