126 = Lieut. Baddeley on the geognosy 
The surface of the rock is strewed with its weathered fragments, 
which exhibit no other change from the rock itself than tha, 
weather has rendered its fissile character more apparent 5 these 
fragments when slightly struck on their edges break into smooth 
rectangular slates. Solid slates five feet long, one foot wide, and 
one or two inches in thickness are seen; fragments of this de- 
scription are very ‘sonorous when struck. 
Afier traversing this clay-slate for about one quarter of a 
mile, the fetid limestone before-mentioned was met with under- 
lying the other conformable strata. Much of this limestone con- 
tains fossil organic remains, chiefly corallites and encrinites ; 
productz were also seen, and a singular fossil similar to a wariety 
found in Drummond’s Island, Lake Huron, of which there is 
a drawing in the sixth volume of the Geological Transactions, 
plate SO, fig. 5, from which that in question appears to differ 
chiefly by having the disks of which it is composed obliquely 
set. on, whereas in the figure alluded to they have a rectangu~ 
Jar position, ‘That from lake St. John also tapers more than 
the other. The cross fracture exhibits a structure which is 
partly compact and partly laminar ; the former appears to pre- 
vail towards the parietes, and to be composed of chalcedony or 
of a carbonate of lime passing into chalcedony; the latter 
eccurs towards the centre, which isacalc-spar. Between the 
two there is also perceived a tendency to the formation of agate, 
chaleedonic rings and curves being distinctly visible. Sometimes 
the centre has nothing of the crystalline aspect whatever, but 
shews a rounded spot of a reddish-brown and opaque substance, 
apparently of the nature of the imbedding rock, which isa dull 
fetid limestone of a dark colour, and full of fossil remains. Close 
to the onc here drawn, but at the back of the specimen, there is 
aproducta. This character of becoming siliceous is common, 
but in a much greater degrec, to the fossils from Drummond’s 
Island, Lake Huron, with the species of which those found on 
Lake 
