mie PALZEONTOLOGY OF NEW-YORK. 
327. 8. GRAPTOLITHUS SAGITTARIUS. 
Pui. LXXIV. Figs. 1 a, b. 
Prionotus sagittarius. Histncrr, Leth. Suecica, Supplement, 1837, pag. 114, pl. 35, fig. 6. 
Graptolithus sagittarius. PorriocK, Geol. Rep. Londonderry, 1843, pag. 320, pl. 19, figs. 8 a b. 
Stipe linear, straight or flexuous, extremely elongated, about one line in width, com- 
pressed; one side smooth and the other serrated; teeth oblique, acute, distant about half 
the width of the stipe. 
This species is readily distinguished from the preceding, by the regular strong serratures 
on one side of the axis only. Specimens of eight or nine inches in length are of frequent 
occurrence, and these are only fragments of much longer ones. It shows no apparent 
increase or diminution of width in either direction, and neither the lower or upper termina- 
tion has been observed. There is, apparently, a capillary axis near the smooth margin, and 
the surrounding substance of the stipe is sometimes of considerable thickness. The character 
is very uniform, showing, in a large number of specimens examined, no important deviation 
from those figured. 
This species is distinguished from the G. clintont of New-York by its shorter and stronger 
teeth, and by the same characters from G. murchisoni and G. sedgwickii of Europe. 
Fig. 1 a. A fragment of the slate, showing three nearly parallel stipes of this species. 
Fig. 1 6. A magnified portion, showing the upper margin of the teeth to be nearly rectangular to the 
direction of the stipe, while the lower side is oblique. 
Position and locality. This species occurs in the glazed and folded black slates on the 
Norman’s kill, near Albany; in the town of Stuyvesant, and near Hudson, Columbia 
county. 
328. 9. GRAPTOLITHUS TENUIS. 
Pu. LXXIV. Figs. 2 a-d. 
Graptolithus tenuis. Porriock, Geol. Rep. Londonderry, pag. 319, pl. 19, fig. 7 a b. 
Stipe very slender, filiform, straight or flexuous, with one side obscurely and distantly 
serrated, the other side smooth. 
This species is readily distinguished from the preceding by the appressed, obscure, and 
more distant serratures. The width in all the specimens examined is less than half that of 
G. sagittarius, and it often appears as if both sides were destitute of serratures. 
Fig. 2 a. Slender elongated stipes of this species, associated with G. sagittarius. 
Fig. 2 }. A portion of one of these magnified. 
Fig. 2c. A small filiform stipe, gradually tapering and bent abruptly backwards. 
Fig. 2 d. A portion of the same magnified, showing the serratures of the same character as the preceding. 
Position and locality. This species has been seen only in the black glazed slates of the 
Norman’s kill, near Albany. 
