106 CONTRIBUTIONS TO CANADIAN PALEONTOLOGY. 



Locality. — Paquette's Rapids, Ottawa River, Birdseye and Black River 

 formation ; collector E. Billings. Specimens were also obtained at this 

 locality by T. C. Weston in 1872. 



Petraia pygmea, Billings. 



Plate VI., figs. 6, 6a, 66. 



Petraia pygmea, Billings. 1862. Palseoz. Foss., vol. I, p. 103, fig. 91. 



Billings. 1866. Cat. Sil. Fdss. of Anticosti, p. 33. 

 Petraia pygmcea, Nicholson. 1875. Palseon. of Ont., p. 59. 



Corallum simple, very small, elongato-conical, gently curved, sometimes 

 slightly constricted above or at mid-length, from 3 to 10 mm. long, aver- 

 aging about 6 mm. in length, and with a breadth at the top generally 

 from about one-third to one-half the length. Outer surface showing faint 

 transverse rings of growth and longitudinal septal markings. Calyx deep, 

 rather pointed below, often reaching more than half way toward the base 

 of the corallum. Septa of two sizes, the primaries in the form of stout, 

 sharp-edged ridges, apparently denticulated, the secondaries, very small 

 but distinct, alternating with the primaries ; in number about twenty- 

 eight. 



Localities. — Collected by J. Richardson in 1856 on the Island of Anti- 

 costi, at Cape Sand Top Bay, division II. Anticosti group ; at Heath 

 Point Lighthouse and at East Point, Ottawa Brook, division III. Anti- 

 costi group ; and at Chaloupe River, division IV. Anticosti group. This 

 coral is found at these localities in large numbers on weathered surfaces 

 of limestone. Nicholson records its occurrence in the Niagara formation 

 at Thorold, Ont. 



PAL^EOCYCLIDiE. 

 Genus Microcyclus, Meek and Worthen. 1868. 



Microcyclus, Meek and Worthen. 1868. Geol. Surv., Illinois, vol. III., p. 420. 



" Corallum free, or with a minute central point of attachment, discoidal, 

 without columella ; calice very shallow, or nearly obsolete, and provided 

 with a single small fosse tte j septa short, nearly regularly radiating, or 

 with a few of those nearest the fossette converging a little towards its 

 sides ; epitheca well developed." (Meek and Worthen.) 



Type species. — M. discus, Meek and Worthen. 



Range. Devonian. (Hamilton formation.) 



