16 B. J. Harrington — Nepheline, Socialite and 



vicinity of Cobourg on the north shore of Lake Ontario, 

 found among these bowlders a number composed of nepheline 

 syenite. The rock composing these bowlders strongly resem- 

 bles in many ways that described in the present paper. Ortho- 

 clase and microcline although present are exceeded in amount 

 by the plagioclase. Eleolite or nepheline usually forms from 

 one-quarter to one-half of the rock, while the rock is some- 

 times a nearly pure eleolite. " Biotite and hornblende much 

 outweigh all the varieties of augite." Calcite grains were 

 found in about one-third of the slides, sometimes "in the 

 midst of the eleolite where their existence is hard to account 

 for. What appears to be a scapolite occupies a similar position 

 in four specimens " and a flesh red garnet also occurs in a few 

 places.* 



Cobourg lies a little to the west of south from the townships 

 of Dungannon and Faraday, and it is highby probable, in view 

 of the marked resemblances between these bowlders described 

 by Prof. Coleman and the nepheline syenite occurring in these 

 townships that the bowlders have been derived from this 

 vicinity. The presence of orthoclase and microcline in many 

 of the bowlders would indicate that all of them at least had 

 not been derived from the actual area described in the present 

 paper, but there is every reason to believe, from the reported 

 occurrence of sodalite at other points in this district, that 

 other areas of similar nepheline syenite exist here, and some 

 of these have probably furnished the bowlders in question. 

 Petrographical Laboratory, McGill College, Montreal. 



Art. III. — On Nepheline, Sodalite and Orthoclase from 

 the Nepheline Syenite of Dungannon, Hastings County, 

 Ontario; by B. J. Harrington. 



In a recent report published by the Geological Survey of 

 Canada and also in the preceding paper, Dr. F. D. Adams has 

 called attention to a remarkable mass of nepheline syenite dis- 

 covered by him in the township of Dungannon and Faraday, 

 Ontario. The rock is in places exceedingly coarse in texture 

 and individuals of nepheline, as much as two and a half feet 

 in diameter have been observed. Dr. Adams has kindly 

 placed a specimen of this nepheline in my hands for examina- 

 tion. It is from near the bank of the York River in Dun- 

 gannon and has been found to have the following percentage 

 composition : 



* Trans, of the Royal Society of Canada, vol. viii, 1890. 



