lambe. ] CANADIAN PALEOZOIC CORALS. 113 



Streptelasma selectum, Billings. (Sp.) 

 Plate VI., figs. 8, 8a. 



Petraia selecta, Billings. 1865. Canadian Naturalist, new series, vol. II., p. 429. 

 Petraia pulcheUa, Billings. 1865. Ibid., p. 429. 



Petraia selecta, Billings. 1866. Cat. Sil. Foss. of Anticosti, pp. 7 and 33. 

 Petraia pulchella, Billings. 1866. Ibid., p. 33. 



Corallum simple, conical, acutely pointed at the base and generally 

 considerably curved below, reaching a length of about 37 mm., measured 

 on the convex curve, and a diameter above of 25 mm. Outer surface 

 frequently showing rings of growth and when not worn longitudinally 

 marked by fine, distinct septal furrows. Calyx steep-sided, having a more 

 or less prominent, conical projection rising centrally from its base, with a 

 depth equal to about one-half the height of the corallum, but sometimes 

 shallower. Septa in the largest specimen numbering about eighty, in 

 smaller specimens between fifty and sixty ; primaries reaching the centre 

 where they are slightly twisted and form with the dissepiments the 

 vesicular mass that projects from the bottom of the cup, secondaries short 

 and inconspicuous. As in the majority of the species of this genus, the 

 primaries frequently unite in sets of twos and threes near the centre of 

 the visceral chamber. In the cup the primaries decrease in size and near 

 the top are scarcely distinguishable from the secondaries ; both orders of 

 septa are apparently denticulated on their thin, free edges and carinated 

 on their sides. Dissepiments curving upward and inward toward the 

 centre between the septa and forming with the inner ends of the primary 

 septa the confused cellulose structure characteristic of the genus. 



Localities. — West End Lighthouse, Anticosti, Que., Hudson River for- 

 mation; also at 1 mile east of Junction Cliff and at White Cliff, Gamache 

 Bay, Anticosti, division I., of the Anticosti group ; J. Richardson, 1856, 

 and T. C. Weston, 1865. 



Streptelasma caliculus, Hall. 

 Plate VII., figs. 4, 4a, 46, 4c. 



Streptelasma calicula, Hall. 1852. Palseon. New York, vol. II. , p. 3, pi. 32, figs. 1 a-k. 



A number of well preserved specimens from Grimsby and Thorold, 

 Ont., and Lake Temiscaming are here referred to Hall's species, but with 

 a certain amount of uncertainty on account of the paucity of structural 

 details given in the original description of S. caliculus. 



These specimens may be described as follows. — Corallum simple, small, 

 conical, slightly curved below and sharply pointed, attaining a length of 

 l— 2 



