94. CANADIAN FOSSILS. 
margins for an inch and a quarter, giving an extremely alate appearance. 
Stipes strong, angular on the back or non-celluliferous margin: test 
thick: cellules unknown. 
The only specimen known consists of the dise and parts of three of the 
stipes ; the longest one extending a little beyond the limits of the dise, or 
so far that the alation produced by the disc is not distinguishable. The 
lower or non-celluliferous side is presented to view, and we know nothing 
of the extension of the stipes, nor of the cellules. It is probably one of 
the simple-stiped species, and of rare occurrence, since no other specimens 
are known which can be identified with it. 
EXPLANATION OF FiGuRE OF GRAPTOLITHUS ALATUS, Hall. 
Pirate VI. 
9. The specimen represented as it occurs on a fragment of slate. The back of the 
stipes shows faint indentations, but they are made too strong in the 
engraving. 
Formation and Locality.—Limestone of the Quebec group; Point 
Lévis. 
18. Grapronitnus Heapr, Hall. 
Plate VI, figure 8. 
(G. Hzant, Hall: Geological Survey of Canada, Report for 1857, page 127.) 
Description.—Frond robust, four-stiped ; the stipes in pairs, jomed by 
a short funicle at the base, and united in a broad thickened quadran- 
gular disc. Stipes strong, somewhat alate near the base from the exten- 
sion of the substance of the disc for a short distance along their margins, 
extremely elongate, and extending in a nearly direct line towards their 
extremities ; celluliferous on one side. The width in a transverse direc- 
tion, at the junction with the disc, is six hundredths of an inch; and m 
the widest portion, fourteen hundredths of an inch. Disc quadrangular, 
nearly square, slightly extended along the stipes, with straight margins in 
the spaces between; measuring in the specimen examined, one inch and 
one eighth in each diameter across the centre. 
Cellules elongate, distinctly curved, making with the axis an angle of 
about 50°; length four or from four to five times the diameter at the 
aperture: denticles sub-mucronate, sub-erect, about twenty-four in the 
space of an inch. The margin of the aperture is apparently curved ; its 
