280 THE CANADIAN NATURALIST. [Vol. viii. 



exposed, the pebbles composing the gravel being in great part 

 limestone from the underlying rocks. So far as known no ice 

 groovings or scratches are visible on either the rock or the imme- 

 diately surrounding limestone, although said to occur not further 

 than half a mile to the south-east. 



The second area of Eozoic rock occurs on a farm belonging 

 formerly to one David Gibson, in lot number 70, Concession II? 

 Ameliasburgh Township, Prince Edward County, and is hence 

 known as " Gibson's Mountain," although, strictly speaking it 

 should be called " Bell's Mountain " from the fact of its having 

 been first studied by Professor J. T. Bell of Albert College. It 

 is situated about six miles to the southwest of Belleville, and is 

 distant from the " Picton road " about half a mile. The mass 

 of rock occupies about fifteen acres, and rises about a hundred 

 and fifteen feet above the plain, the greatest height occurring 

 near its north end where it is bold and bluffiish, while like the 

 Shannonville outlier it dies gradually down to the south-west. It 

 strikes north-east and south-west and is intersected by several 

 small fissures; one, the most important nearly separating it into 

 two masses. It presents the typical mammillated appearance of 

 true Laurentian rock, and is similar in lithological aspect to this. 

 It is composed principally of a flesh-red and dark-red orthoclase, 

 the colour varying from nearly white to dark red, a small per 

 centage of translucent quartz, a little dark green hornblende and 

 a very little black mica, the two latter minerals being generally 

 absent, and hence externally the rock is of a pale pink to dark red. 

 Although several good sections are exposed — one in particular 

 occurring where a downthrow of twelve feet has " slickensided " 

 the rocks on one side and formed a small " valley of dislocation" 

 with a strike of N. 23° E. — there is no distinct appearance of 

 stratification in these. There are, on the contrary, several places 

 where the rock becomes decidedly porphyritic, crystals of ortho- 

 clase of two inches in length having been met with there. Still 

 its very close analogy with the more distinctly stratified rocks 

 of the same lithological character iu Labrador would cause one 

 to describe it as a true Laurentian, very feldspathic, somewhat 

 what porphyritic, coarse-grained, granitoid, syenitic gneiss. It 

 is said to agree topographically with the u lied Hills" of Madoc 

 Township, Hastings County, while it certainly appears to be 

 almost identical with them lithologically, judging from the de- 

 scriptions given by Prof. McCoun and other observers. Like 



