100 CONTRIBUTIONS TO CANADIAN PALEONTOLOGY. 



Columnaria Halli, Nicholson. 



(Non Columnaria alveolata, Goldfuss.) 



Plate VI., figs. 2, 2a. 



Columnaria alveolata, Hall. 1847. Palseon. New York, vol. I., p. 47, pi. 12, figs. 1, 

 la - -c. 



Billings. 1863. Geology of Canada, p. 139, fig. 70. 

 n ii Nicholson. 1875. Palseon. of Ont., p. 8. 



H .1 Rominger. 1876. Geol. Sur. Mich., Foss. Corals, p. 89, pi. 



XXXIV., figs. 1, 2 and 4. 

 Columnaria (?) Halli, Nicholson. 1879. Palseoz. Tab. Corals, p. 200, pi. X., figs. 3, 

 3a. 



Corallum attaining to a considerable size and formed of polygonal 

 corallites in close contiguity throughout their length. The corallites vary 

 in width from 4 to nearly 11 mm., and are much more irregular in size 

 than in C. alveolata, Goldfuss. The septa, in the form of lamellar keels 

 and numbering in all from about twenty-five to forty, are of nearly equal 

 size and project only a short distance into the visceral chamber ; their 

 free edges are denticulated and in well preserved specimens their differ- 

 entiation into two alternating sizes is distinctly seen. The tabulae are 

 horizontal, entire, often slightly concave or convex, but not turned down 

 at the edges, nor crenulated as is frequently the case in C. alveolata. In 

 some specimens the division line between the corallites can be seen clearly 

 in transverse section or when weathering has taken place. The initial 

 corallites seem to be larger as a rule than those of the corallum when it 

 has attained a larger growth. 



This species is typical of the Birdseye and Black River formation in 

 the provinces of Quebec and Ontario. In the Geology of Canada, 1863, 

 it is recorded as occurring in the province of Quebec at Montreal and 

 Pointe Claire, at St. Lin and Joliette, north of Montreal, also on the 

 Riviere au Lard, Cap de la Magdelaine township, county of Champlain. 



In the museum of the Survey it is represented by specimens from 

 Paquette's Rapids, Ottawa River ; from Cornwall township, county of 

 Stormont, Ont. ; from Pakenham, McNab and Stafford townships west 

 of Ottawa ; from Rockland quarry in the vicinity of Ottawa ; from St. 

 Vincent de Paul, Isle Jesus, Que. ; from Riviere au Lard, county of 

 Champlain ; also from Gravel Point, St. Joseph Island, Lake Huron and 

 from the west shore of Great Manitou Island, Lake Nipissing, Ont. 



The specimen of C. Halli, from which the figures on plate VI. are 

 taken, is from the Black River limestone at Stewart's quarry, near Sand 

 Point, on the Ottawa River, a few miles west of Arnprior. 



