96 CANADIAN FOSSILS. 
the base; the free portion is a little more than one third of the entire 
length. Margin of aperture slightly curved in the mature cell, and more 
distinctly in the young, making in the former an angle of 120° with the 
axis. ‘The denticles are pointed, scarcely sub-mucronate, twenty-four in 
the space of an inch. Cell-partitions strongly marked, the line of sepa- 
ration extending nearly to the back of the stipe. 
In this species the stipes resemble those of G. bryonotdes in their width, 
form, and proportion of cellules and cell-denticles ; but the number of 
stipes in entire specimens is a characteristic feature. In single stipes or 
in pairs of G. octonarius, there is, as shown in the figures, a longer space 
at the base without cellules, and in the double or quadruple stipes the differ- 
ence of character is obvious. In the union of the two stipes in G. bryonoides, 
the funicle proceeds from the back of the stipes, or the non-celluliferous 
side; while in the union of two stipes in G. octonarius, the continuation below, 
uniting with the adjacent pair, is not from the back of the stipes alone, but 
the two appear to be united laterally and diverge at a different angle ; as 
will be seen on comparing the figures of the two species. Fragments of 
G. patulus bear some resemblance to this species, but a comparison shows 
important differences. 
EXPLANATIONS OF FIGURES OF GRAPTOLITHUS OcTONARIUS, Hall. 
PuatTe X. 
1, A specimen of natural size, much broken and distorted from pressure. 
2. An enlargement from the preceding figure. 
Formation and Locality.—Shales of the Quebec group; Grds Maule. 
20. GRAPTOLITHUS OCTOBRACHIATUS, Hall. 
Plate VII, figures 1-7; and Plate VIII, figures 1-4. 
(G. ocrosracuiatus, Hall: Geological Survey of Canada, Report for 1857, page 122.) 
Description.—Frond consisting of eight simple stipes, which are united 
in pairs at their bases: these have their origin from a short funicle, 
which proceeds from a radicle in the centre. Each extremity of the funicle 
is divided, and these divisions are again bifurcated, giving origin to the 
four stipes on each side, which are thus bilaterally arranged. The funicle 
and bases of the stipes are united in a broad thickened disc, composed of 
the same substance as the other parts of the fossil: disc octagonal, the 
