12 TRANSACTIONS OF THE ROYAL CANADIAN INSTITUTE. [VOL. XI 
COLUMNARIA RUGOSA, Billings sp. 
LITHOSTROTION STOKESI, Milne-Edwards and Haime. Polyp. Foss. des Terr. Palaeoz., 
Pp. 440, pl. 20, fig. 2, 1851. 
PALAEOPHYLLUM RUGOSUM, Billings. Geol. Sur. Can., Rep. Prog. for 1857, p. 168, 1858. 
COLUMNARIA ERRATICA, Billings. Ibid. p. 166, 1858. 
DIPHYPHYLLUM STOKESI, Whiteaves. Geol. Sur. Can., Pal. Foss., Vol. III, pt. III, p. 152, 
pl. XVII, figs. 5, 5a, 5b. 
COLUMNARIA RUGOSA, Lambe. Ottawa Naturalist, Vol. XII, p. 217, 1899. 
COLUMNARIA RUGOSA, Lambe. Con. Can. Pal., Vol. IV, pt. II, p. 1o1, pl. III, figs. 3, 3a, 
3b, 1900. 
COLUMNARIA RUGOSA, Parks. Bur. Mines Ont., 22nd Rep., p. 190, 1913. 
A well preserved fragment showing about fifty corallites. Lambe 
gives the corallites of this species a diameter varying from three to 
nine millimetres: the maximum diameter of our corallites is six milli- 
metres with an average considerably less. Lambe also states that the 
tabule occur to the number of four in a distance of two millimetres: 
while this is true in parts of our specimen, a much wider spacing is 
observed in others. There can be little doubt, despite these trifling 
differences, that this specimen is referable to C. rugosa. 
Locality—Lower rapids, Shamattawa river, Manitoba. 
Horizon—Ordovician. } 
No. 291 S. Royal Ontario Museum of Palaeontology. 
STREPTELASMA cf. RUSTICUM, Billings. 
Plate V, Figures 4 and 5. \ 
STREPTELASMA CORNICULUM, Milne-Edwards and Haime. Polyp. Foss. des Terr. Palaeoz., 
p. 398, pl. 7, figs. 4, 4a, 4b, 1851. 
PETRAIA RUSTICA, Billings. Geol. Sur. Can., Rep. for 1857, p. 168, 1858. 
ZAPHRENTIS CANADENSIS, Billings. Geol. Sur. Can., Pal. Foss., Vol. I, p. 105, figs. 93a-c, 
1862. 
PETRAIA CANADENSIS, Billings. Geol. Sur. Can., Rep. 1863, p. 208, fig. 205. 
STREPTELASMA CORNICULUM, Nicholson. Pal. Ont., p. 26, 1875, and Geol. Sur. Ohio, 
Vol. II, p. 218, 1875. 
STREPTELASMA CORNICULUM, Rominger. Geol. Sur. Mich., Foss. Corals, p. 141 (pars), 
p!. LI, upper row, specimens from the Hudson River 
formation only, 1876. 
STREPTELASMA RuUSTICUM, Lambe. Geol. Sur. Can., Cont. to Can. Pal., Vol. IV, pt. II, 
p. 110, pl. VII, figs. 2, 2a and 3, 1900. 
STREPTELASMA CORNICULUM, Parks. Bur. Mines Ont., 22nd Rep., p. 190, 1913. 
The specimen in this instance is a single broken corallum showing 
neither calyx or apex: it is 41 mm. long and presents a diameter at the 
anterior end of 33 mm. The posterior diameter is 25 mm. The general 
form of the corallum in the portion preserved is nearly straight. The 
exterior is smooth and is apparently covered by a complete epitheca, 
as the septal markings are not to be observed. 
