252 The Ottawa Naturalist. [March 



an axial vesicular mass whose surface appears in the calyx as a 

 rounded protuberance. Surrounding the central area is a broad 

 vesicular zone in which can be detected the gradual growth up- 

 ward of the corallum by the superposition of vesicular layers, 2 

 or 3 mm. in thickness, each layer terminating above in a thin 

 covering of flexuous, continuous laminre representing the position 

 of the surface of previous calyces. The convex plates compos- 

 ing the vesicular layers are small, generally i mm. or less in 

 length. The septa, starting at the confines of the centra! vescular 

 area, radiate outward as thin vertical laminae and disappear in 

 the peripheral region ; they are represented on the calicular 

 surface by the gradually broadening superficial convex ribs that 

 are connected with each other laterally. In tangential sections at 

 the margin of the calicular expansions the cut edges of the septal 

 ribs, here about 3 mm. in breadth, appear as horizontal con- 

 tinuous parallel wavy lines. What appear to be septal carini© 

 or possibly structures analogous to the supporting processes of 

 the septal laminae as developed in some species of the genus are 

 seen in the radial section of the corallum. 



Locality and formation. — Anse k la Vieille, Bale des Chaleurs, 

 one specimen collected by Sir W. E. Logan in 1843 ; Lower 

 Helderberg formation. 



Zaphrentis gigantea, Lesueur, sp. 



Caryophyllia gigantea, Lesueur. 1820. Mem. du Mus., t. VI, 

 p. 296. 



Zaphrentis gigantea,y[\\x\Q-Y.di\N^x^s?iX\AW^\ri\t. 185 1. Polyp. 



Foss. Terr. Palaeoz., p. 340, pi. IV, figs, i, la-c. 

 " gigantea, Billings. 1859. Canad. Journ., vol. iv, new 



series, p. 121, 

 " gigantea, Nicholson, 1874. Rep. Palaeont.. Prov. 



Ontario, p. 22, pi. iii, figs, i, la. 



Eriphyle, Billings. 1875. Canad. Nat. and Geol., 



vol. VII, 2nd. series, p. 233. 

 " Hecuba, Billings. 1875. Ibid, p. 234. * 



" gigantea, Rominger. 1876. Geol. Surv. Michigan, 



Fossil Corals, p. 145, pi, lii. 





