lambe.] CAANDIAN PALEOZOIC CORALS. 69 



acteristic yellow dolomite, and do not show any very minute details of 

 structure ; there are indications of spiniform septa, but tubules so far have 

 not been recognized with any degree of certainty, although there are 

 evidences of what might be tubules with rather arched tabulae. Mr. 

 Whiteaves records the occurrence of H. catenularia in the Guelph for- 

 mation of Ontario (vide Pal. Foss. vol. III., pt. II., p. 47), at Guelph, 

 collected by E. Billings, 1857 ; at Elora, R. Bell, 1861 ; at Hespeler, T.C. 

 Weston, 1867 ; and at Durham, J. Townsend, 1878—82. 



Halysites catenularia, var. Quebecensis. (Var. nov.) 



Plate IV., figs. 1, la, 16. 



In the Geology of Canada, 1863, p. 165, Billthgs mentions the occur- 

 rence of H. catenularia at Lake St. John, Que. Speaking of the lower 

 Silurian strata exposed between the mouth of the Metabechouan River and 

 Blue Point, h« says, " the lower rocks of the series are limestones, and 

 their fossils indicate that they belong to the Birdseye and Black River and 



Trenton formations." The chief part of the limestones are of a 



yellowish-grey, and at the Ouiatchouan in a three foot bed of this descrip- 

 tion at the base of the series there was met with Halysites catenu- 



latus, in no other place found so low on the American continent." The 

 specimens from this locality bear a strong resemblance in outward form 

 to H. escharoides, Lam., as figured by Goldfuss in the Petrefacta Ger- 

 manise, vol. 1, figs. 4a, 46. 4c. In most of the specimens the inner 

 structure is difficult to make out, but in one specimen in particular re- 

 markably narrow tubules are observed. The corallites are oval and the 

 tabulae rather flat and not very close together. This variety can be 

 recognized by its general form of growth with small meshes and rather 

 small corallites, and by the presence of very narrow tubules with rather 

 distant, flat tabulae. Some of the most perfect specimens are hemi- 

 spherical in shape and attain a breadth of 6 to 8 inches. 



Halysites catenularia, var. gracilis, Hall. 



Plate III., figs. 5, 5a, 56, 6 and 7. 



Catenipora gracilis, Hall. 1851. Geol. Lake Superior Land Diat., vol. 2, p. 212, pi. 

 XXIX., fig. la, 16. 



This form is distinctive of the Galena- Trenton, as it occurs at Lake 

 Winnipeg and further north, and of the Hudson River formation in Anti- 

 costi and the province of Ontario. Hall described this form in 1851 as 

 a distinct species under the name H. gracilis. The rocks of Hudson 

 River age at Green Bay, Wisconsin, from which the specimen described 



