10 CANADIAN FOSSILS. 
are no cellules below the last bifurcation. The number of stipes in different 
individuals varies from sixteen to twenty-five, so that this charactercannot 
be made of specific importance. In another similar species without a central 
disc, from the Hudson River formation, we have above forty stipes, which do 
not bifurcate, so far as known, beyond the commencement of the cellules. 
Fig. 7. 
GRAPTOLITHUS MULTIFASCIATUS. 
The separated and broken stipes referred by me to Graptolithus sagit- 
tarius* are probably of this species, occurring as they do in great numbers 
in the same beds in which this was found. 
In other species with a similar general arrangement of parts, the main 
stipes are frequently bifurcated ; the bifurcations beginning near the base, 
and continuing as far as the parts can be traced in the stone (fig. 8). 
In some of the species of this character the cellules begin near the base 
of the stipes, while in one species they are not known to exist except 
on the outer branchlets. 
Thus far we trace these forms through what appear to be very natural 
stages in the progress of development of the parts, which are all constructed 
upon the same plan, presenting only natural, and we may almost say con- 
sequent modifications. 
The character of stipes and cellules in all these is such that the sepa- 
rated fragments would afford no means of indicating whether the part 
belonged to a two, four, or eight-stiped species, or to those with numerous 
simple stipes, or with branching stipes, unless the fragment retained a 
bifurcation. 
A variety of form is exhibited in the division termed Dendrograptus, 
in which we may conceive of the numerous stipes near the base becoming 
* Paleontology of New York, vol. i, page 272, pl. 74, fig. 1. 
