GRAPTOLITES. 87 
be determined. Examinations have failed to exhibit any satisfactory 
evidences of the existence of a radicle. In most of the specimens the 
stipes are united at one extremity and free at the other; while their curva- 
ture is such, that if continued, they would meet. In these specimens the 
four stipes are often distinctly seen, two usually showing the non-celluli- 
ferous margins; while sometimes three, and rarely the four stipes show the 
celluliferous margins. 
The individuals are extremely numerous, but in almost all instances the 
characters are more or less obscured by the stipes being slightly separated 
by intervening lamin of slate, or by the weathering of the surface. On 
a single piece of slate of about a foot long by six inches wide, there are 
more than one hundred individuals ; but nearly all of these are so obscured 
by weathering, that they afford little means of determining the characters or 
mode of growth. In the whole collection, there are not more than one or 
two species of which the individuals are more numerous than of this, and 
in no other are the characters so indistinct. 
From the deep curving cellules and broad stipes, which are often appa- 
rently conjoined at the apex, I have supposed that they may, at some period 
of growth, have been jomed along the non-celluliferous side for the entire 
length. On this account, I had originally referred the species to the 
genus Phyllograptus. 
In some of the specimens, where two of the stipes are spreading, and 
show the celluliferous margins, the non-celluliferous face of a third stipe 
often stands vertically between them, like a stem. These forms resemble 
the Graptolithus caduceus of Salter, which was obtained by Dr. Bigsby 
from ‘‘ the Lauzon Precipice,” * and I have hesitated in regard to making 
of these a new species. The name of Phyllograptus similis was applied to 
such forms as figs. 26, 29, and 30; but when it became apparent that all the 
other varieties of form must be referred to the same, it was necessary to 
remove it from that genus; and since I had already named another spe- 
cies Graptolithus similis, I take great pleasure in dedicating this to Dr. 
J.J. Bigsby, who early explored the geology of the northern portion of 
our continent, and who, in later years, has never ceased to interest himself 
in American geology, and to aid in its progress. 
EXPLANATIONS oF Figures or Graprouiruus Biessyi, Hall. 
Prats XVI. 
22,23, and 24 illustrate a common condition of this species, where two of the 
divisions show the lateral faces, while the non-celluliferous edge of a 
* This locality is probably the same with that which has furnished the greater part 
of the graptolites here described; the precipitous heights of Point Lévis being in the 
seigniory of Lauzon. 
