244 The Ottawa Naturalist. [March 



CyatJwpJiyllum Eriphyle, Billings. 1862. Geol. Surv. Canada, 

 Palaeoz. Fossils, vol. i, p. iii. 



Corallum simple, large, cylindro-turbinate. Outer surface 

 marked transversely with shallow constrictions alternating with 

 low growth-swellings, 5 or 6 mm. broad, representing successive 

 calicular margins. Epitheca thin, with numerous transverse 

 growth-lines and longitudinal depressed linear markings 2 or 3 

 mm. apart. Internal structure, as viewed in longitudinal and 

 transverse sections, composed of a central tabulate area, about 

 one-third the diameter of the corallite, surrrounded by a broad 

 vesicular zone. Tabulae flat, close set, moderately regular, some- 

 times anastomosing, about twelve in a space of i cent. Vesicles 

 unequal in size, from i or 2 mm. to over i cent, in length, made 

 up of arched plates curving upward and outward. The tabulge 

 are at intervals continued obliquely outward over the vesicles so 

 as to form in reality a succession of invaginated cups flat at the 

 bottom with dilated convex sides. Septa discontinuous 

 vertically, formed by the infolding of the sides of the cups, 

 broad and angular at the periphery, becoming lamellar within, 

 not encroaching on the tabulate area, numbering about eighty 

 and apparently of equal length. Calyx moderately deep. Length 

 from 10 to 25 cent; diameter from 5 to 6*5 cent. 



Locality and formation. — Anse a la Vieille, Baie des Chal- 

 eurs, collected by Sir W. E. Logan in 1843 ; Lower Helderberg 

 formation. 



Arachnophyllum DIFFLUENS, Milne-Edwards and Haime, sp. 



Strombodes dtffluens, Milne-Edwards and Haime. 185 1. Polyp. 

 Foss. Terr. Palaeoz., p. 431. 



" diffluens, Milne-Edwards and Haime 1855. Brit. 



J^oss. Corals, 294, pi. LXXI, ngs. 2, 2a. 



" diffluens, Billings. 1866. Geol. Surv. Canada, Cat. 



Silur. Foss. Anticosti, p. 34. 



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



Fossil Corals, p. 131, pi. XLVIII, fig. 3. 



