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CRETACEOUS AND TERTIARY—ST. MARY RIVER. 133 
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followed in ascending order by a hard shell-bed eighteen inches to two ar 
feet thick, dark-coloured from included carbonaceous matter, but in the ~ “a 
main composed of shells of Ostrea and Cyrena. Above this is a con- 
siderable thickness of flaggy and ripple-marked sandstones, greyish and 
brownish-grey, with a dip of S. 28° W. < 35°. The ripple-marks 
indicate a current with a direction of S. 14° W. (mag.) 
327. A few hundred yards south-east of the last exposure, sand- 
stones similar to those overlying the coal are found well shown in a 
steep bank. (Plate IX., Fig. 2.) They are sharply folded into an anti- 
¢linal form, and are overlaid by a considerable thickness of greenish-grey 
clay beds. The latter are charged with small flat masses of calcite, formed 
apparently in fissures, but now scattered over the surface of the clay- 
ce bank, giving it a remarkable appearance. <A sheil-bed very similar to 
that found in connection with the coal, but probably not identical with | : 
it, as it wants the carbonaceous colouring matter, also appears here. ; 
It probably underlies the sandstone, but though large blocks of it are 
‘strewn about, it is not very well exposed. The rocks are so abruptly 
folded that they appear in some places to be slightly overturned; and in 
_the absence of large or continuous sections, the precise relations of the 
beds cannot be traced. | | 
te 328. About two miles northward on the same river, it cuts through 
high banks which exhibit similar rocks. It here seems to follow still 
ay more Closely the line of fracture of the country, the beds on the east 
| side being not far from horizontal, while those on the west are much 
disturbed, the lithological character and general appearance of both 
‘series being, however, much alike. No coal-beds, or beds containing 
fossils were seen here. 
329. Four miles west of the St. Mary River, a hard fossiliferous bed 
comes to the surface, forming the crest of a ridge. It dips west-south- 
west, at an angle of 20°. Where exposed, it is an almost solid mass of 
fossil shells, forming a rough limestone. The same molluscs are repres- 
ented here as in the other sections in the locality of St. Mary River, the 
most abundant being a species each of Cyrena and Ostrea. The former 
is probably C. occidentalis, M. & H., and in some of its forms is scarcely 
distinguishable from C. cordata, Morris, a shell of the English Kocene.* 
The Ostrea is a large shell, trigonal, and very massive, but not yet 
specifically determined. 
* Figured in Journ. Geological Society, Vol. X. Meek, compares C. occidentalis with this species, 
