58 



NEW YORK STATE MUSEUM 



3 SYNOPTIC TABLE OF THE DISTRIBUTION OF THE GRAPTOLITES OF THE DEVOMC OF THE 



UNITED STATES 



i Dictyonema crassum Girty . 



2 D. leroyense Gurley ms. . . . 



3 D. megadictyon Gurley ms. 



4 D. perradiatum Gurley ms. 



5 D. fenestratum Hall 



6 D. hamiltoniae Hall 



7 Ptiograptus percorrugatus Ruedemann . 



8 Desmograptus becraftensis Ruedemann. 



9 D. cadens (Hall) 



to D. vandelooi Ruedemann 



ii Monograptus beecheri Girty 



OTHF.R 

 REGIONS 



Ontario, 

 Canada 



From Canada have become known : Dictyonema splendens 

 Billings and Chaunograptus gracilis Clarke, both from the early 

 Devonic of Gaspe, Province of Quebec. Of the 1 1 species, credited to the 

 United States, no less than 9 forms are derived from the Devonic rocks of 

 New York. Two of these, Dictyonema crassum and Desmo- 

 graptus becraftensis, are found in the New Scotland beds of 

 Becraft mountain, the former also in those of the Helderbergs. The New- 

 Scotland beds of the Indian Ladder have also furnished the single repre- 

 sentative of the Graptoloidea, Monograptus beecheri. Three 

 species, viz, Dictyonema leroyense, D. megadictyon and 

 D. perradiatum are from the Onondaga limestone of Leroy in 

 western New York, the last also being observed in the same formation in 

 Ontario, Canada. 



The Hamilton beds of New York contain three species of graptolites. 

 Two Devonic types, Dictyonema fenestratum and Ptiograp- 

 tus percorrugatus, are from western beds. 



