504 
PALAEONTOLOGY OP NEW-YORK. 
son of specimens from more southern localities, with those of New-York, shows a 
large proportion of new species; and it now appears probable that the number of 
American species of Graptolithus previously known (about twenty), will soon be 
increased by an equal number of new ones. 
Locality and formation. Point Levy, Canada : Hudson-river group. 
In addition to the species above noticed 
, the following are 
published in the same 
Report for 1857 : 
• 
Graptolithus 
FLEXILIS, 
GRAPTOLITHUS 
INDENTUS, 
G. 
RIGIDUS, 
G. 
NITIDUS, 
G. 
OCTOBRACHIATUS, 
G. 
BIFIDUS, 
G. 
OCTONARIUS, 
G. 
PATULUS, 
G. 
QUADRIBRACHIATUS, 
G. 
EXTENSUS, 
G. 
CRUCIFER, 
G. 
DENTICULATUS, 
G. 
BRYONOIDES, 
G. 
PRISTINIFORMIS, 
G. 
HEADI, 
G. 
ensiformis, and 
G. 
ALATUS, 
G. 
TENTACULATUS. 
G. 
FRUTICOSUS, 
Besides these 
species of Graptolithus, there are some other forms 
in the Canadian collection, separated by the writer under the name 
Phyllograptus, as follows : 
Genus Phyllograptus. 
Frond consisting of simple foliate expansions, celluliferous or serrated 
upon the two opposite sides : margins with a mucronate extension from 
each cellule; or of similar foliate forms united rectangularly by their 
longitudinal axes, and furnished on their outer margins with similar 
cellules or serratures, the whole supported on a slender radicle. 
These bodies, which usually appear upon the stone in the form of simple leaf-like 
expansions, may possibly have been attached in groups to some other support; but 
the form of some of them, and the character of the projecting radicle at the base, 
indicate that we have the entire frond. These forms furnish perhaps the best illu¬ 
stration of all the Graptolitidea , of the lesser development of the cells at the base, 
and their gradual expansion above until they reach the middle or upper part of the 
frond. Many of them diminish from the centre upwards; and rarely the cells are 
more developed above the centre, reversing the usual form, and leaving the nar¬ 
rower part at the base. 
