lavbh.] CANADIAN PALAEOZOIC CORALS. 179 



Omphyma. verrucosa, Milne-Ed wards and Haime. 1851. Polyp. Foss. des Terr. Palaeoz., 



p. 403. 

 Zaphrentis Bigshyi, Billings. 1866. Cat. Sil. Foss. of Anticosti, p. 92. 

 Omphyma verrucosa, Rominger. 1876. Geol. Sur. Mich.. Foss. Corals, p. 117, pi. XLIV., 



lower row. 



The description given by Milne-Edwards and Haime is as follows : 

 " Cette espece est allongee, cylindro-turbinee, souvent courbee ; les bour- 

 relets d'accroissement sont tres-prononces ; ses prolongements radiciformes 

 espaces, mais quelquefois situes tres-pres du calice. Sa hauteur est d'en- 

 viron 6 ou 7 centimetres ; le diametre du calice est de 3 ou 4. 



" Silurien. Amerique du Nord : He de Drummond sur le lac Huron. 



"Coll. Stokes." 



With this species are identified two exfoliated specimens from the 

 Niagara of Grand Manitoulin Island, Lake Huron, collected by Mr. J. 

 Townsend in 1883. The specimen described by Mr. Billings under the 

 name Zaphrentis Bigshyi is from rocks of the same age on the east side of 

 Cockburn Island, two miles north of McLeod's Harbour, collected by R 

 Bell in 1866. 



Rominger's specific description is as follows : — 



"Conical polyparia, attaining in larger specimens the length of one 

 decimeter by a calyx diameter of from seven to eight centimeters. Sur- 

 face of the silicified specimens generally exfoliated ; if perfect, it is 

 covered by an epithecal wall with annular wrinkles of growth, and longi- 

 tudinally striate by septal furrows. From the sides of the conical walls 

 numerous cylindrical, root-like prolongations grow out, serving for attach- 

 ment of the coral to other bodies : these appendices were not distributed 

 equally over the surface, but seemed to form only on those sides where a 

 chance for attachment was offered by close proximity of an object. 

 Calyces spacious, with steeply ascending sides and a gently expanded 

 margin ; bottom broad, convex, with depressed circumference, flat or 

 somewhat concave in the centre, which may be almost smooth, or the 

 lamellae may extend over it as carinations, becoming twisted in the centre. 

 On the ascending sides of the calyx the lamellae have the form of acute 

 linear laminae alternating in size, a smaller and a larger one near the bot- 

 tom of the calyx always united into pairs. In the marginal portions of 

 the calyces, the two plates forming the linear crests diverge at the base, 

 and open into a tent-shape. The four septal foveae are scarcely ever 

 distinct — two of them, or it may be only one, being plainly developed. 



" The centre of the polyparia is, in vertical sections, seen regularly 

 intersected by large transverse plates, and the continuity of the vertical 

 crests is interrupted. Number of lamellae in calyces of six or seven centi- 

 meters diameter from one hundred to one hundred and ten, Associated 

 L— 6J 



