. Annual report. New York State Museum; Science; Science. GRAPTOLITES OF NEW YORK, PART 2 365 1901, similar characters and have frequently been identified with D. amplexi- c a u 1 i s and which quite surely have descended from this form. Only few of these shale specimens, as that reproduced in plate 25, figure 12, will exhibit the characteristic imbricating of the thecae along the median line. a Diplograptus amplexicaulis var. pertenuis nov. Plate 25, figures 14-16 Diplograptus amplexicaule Whitfield. U. S. Geog. Sur. AVest iooth- Merid. Wheeler's Rep't. v. 4, Pal. 1877. p. 19 Diplograptus amp
. Annual report. New York State Museum; Science; Science. GRAPTOLITES OF NEW YORK, PART 2 365 1901, similar characters and have frequently been identified with D. amplexi- c a u 1 i s and which quite surely have descended from this form. Only few of these shale specimens, as that reproduced in plate 25, figure 12, will exhibit the characteristic imbricating of the thecae along the median line. a Diplograptus amplexicaulis var. pertenuis nov. Plate 25, figures 14-16 Diplograptus amplexicaule Whitfield. U. S. Geog. Sur. AVest iooth- Merid. Wheeler's Rep't. v. 4, Pal. 1877. p. 19 Diplograptus amplexicaulis •Ruedemann. N. Y. State Mus. Bui. 42. P-533ff Professor Whitfield in 1875 writes: Just south of Troy, in the shaly partings between layers of metamorphic limestone, I have found a species of Graptolite in great abundance undistinguishable from G. amplexicaule Hall, from the Trenton limestone of Herkimer county, N. Y. The same species was also found abundantly in the yard of the arsenal at Water- vliet by Capt. C. E. Dutton, U. S. A. The present writer has afterwards found the same form in numerous localities in the region \ \f~7 indicated by Whitfield, associated with other Trenton forms. In most localities as at Water- Fig. 308-10 Diplograptus am- vliet, it is the only graptolite observed and com- ^^^l^J^^^i I * r*11 • 1 11 1 1 • from Ruscher's quarry, Troy; that of pletely nils the rock there; at the power house in figure3o9;sfromLansingburg. x5 Lansingburg it is equally common in one layer and there associated with a transitional fauna. After more thorough comparison of the Trenton limestone specimens and those from the shales of the D. amplexicaulis zone, it has been found that while the latter exactly agree in form and closeness of arrangement of thecae with the Trenton limestone types of the species, they are distinctly and uniformly narrower. It is true, there are limestone specimens, equally narrow as that reproduced in figure 304, but they are extremes
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