GRAPTOLITES. ‘ 75 
allel direction. Test somewhat rough : width of stipe about six hundredths 
of an inch; the back marked by a strong axis, and a scarcely appreciable 
portion occupied by the common body. Cellules narrow, distant, about 
twenty in the space of an mch; each one having a length of about three 
times its width, half of the length being free ; inclined at an angle of. 
about 35° to the axis: aperture at right angles to the axis; the apex 
acute and pointed. 
This species bears a resemblance to G. extenwatus in the width of stipe 
and proportional distance of cellules; but the angle of inclmation of the 
cellules and the form of aperture are quite different ; the absence of 
pustules at the base of the cell-divisions is also a very distinctive character. 
The stipes of this species bear a very close resemblance to those of G. 
quadribrachiatus ; but the individual figured, in which the base is pre- 
served, shows in its peculiar curving and smaller serratures near the base, a 
feature which belongs only to the two-stiped forms. The cellules also 
appear to be narrower, and are slightly closer in their arrangement ; 
stipes of the same size of the two species, showing respectively eighteen 
and twenty cellules in equal spaces. 
EXPLANATION or Ficure or GRAPTOLITHUS INDENTUS, Hall. 
Puate I. 
20. An individual of the natural size, the continuation of the stipes having been 
broken off. 
Formation and Locality.—Shales of the Quebec group; Pomt Lévis. 
}. GRAPTOLITHUS EXTENUATUS, Hall. (n. s.) 
Plate I, figures 21, 22. 
Description. —Stipe slender, linear, straight ; substance smooth, except 
the striz mdicating the cell-partitions ; width a little less than one 
twentieth of an mch, the common body occupying a little more than one 
quarter of the width. The back of the stipe is marked by a strong marginal 
axis. Radicle unknown. 
Cellules narrow, very gradually expanding from the base, length about 
three and a half times the width ; making an angle with the axis of nearly 
20°, and curved near the base. Apertures truncate, slightly curved to- 
wards the anterior margin, and nearly at right angles with the axis; free 
for about two fifths of their length ; about twenty-four in the space of an 
