514 
PALAEONTOLOGY OF NEW-YORK. 
from their appearance and relation to the serratures, I infer that they are of more 
importance in the organization than simply as ornament. 
Graptolithus divaricatus. 
Fig. 1, A large individual, where the divergence of the parts is much greater than in figure 3. The 
figures are twice the natural size of the specimens. 
Fig. 2. A part of the stipe still farther enlarged, showing the serratures and the small nodes. 
Fig. 3. An individual, where the divergence is less than 90 degrees. 
Fig. 4. A part of fig. 3 much enlarged, to show the form of the serrature. 
Geological position and locality. In the shales of the Hudson-river group : Nor- 
manskill near Albany. 
Graptolitlius marcidus (n. s ). 
Frond simple, biserrate : stipe short, rigid; midrib strong; serrations 
deep, the denticles small, triangular, subobtuse, arranged in the pro¬ 
portion of twenty-eight to thirty-two in the space of an inch, often 
somewhat alternating on opposite sides of the stipe, which is terminated 
below by two or three longer denticles which are of the same substance 
as the body of the stipe. The apex is marked by an extended fibre or 
continuation of the axis. 
The specimens of this species which I have seen are usually not more than from 
one-half to seven-eighths of an inch in length. The axis is narrow; the points of the 
serrations separated, leaving a defined triangular indentation; and the aspect is 
that of a contracted or shrunken stipe, and by this character alone is very readily 
distinguished. It has been observed in considerable numbers, so that we can have 
no doubt as to the constancy of its characters. 
