GRAPTOLITES OF NEW YORK, PART 2 



I49 



built. In its general appearance it also recalls two Bohemian forms, viz, 

 P. ramale and glomeratus Poet a, both from D0I3 and hence of 

 approximately equal age. These, however, do not show any prominent 

 thecae, but instead exhibit a distinctly fibrous structure of the branches. 



Ptilograptus hartnageli sp. now 



Plate 1 , figure 9 



Description. Frond very delicate (branch and branchlets not more 

 than .2 mm wide). Branch (probably not quite complete) 7 mm long, dis- 

 tinctly zigzagged; branchlets (pinnules) about 

 4 mm long and diverging from the branch at 

 40". There are five of them counted on either 

 side of the branch in the fragment. The 

 thecae are quite distinct, their ventral margin 

 diverging about 20° from the axis of the 

 branchlet ; they are conical ; overlap about one 

 quarter their length, possess straight or slightly 

 convex ventral margins and straight dorsal 

 margins and number 16 to 1 7 in 10 mm. 



Position and locality. One specimen col- 

 lected in greenish-gray Clinton shale above the 

 iron ore at Sterling station, Cayuga co., N. Y. 

 by Mr C. A. Hartnagel. 



Remarks. The specimen while beautifully preserved in. its details, is 

 clearly but a fragment of a larger rhabdosome. From the only other Siluric 

 congener on this side of the Atlantic, P. foliaceus Spencer from the 

 Niagaran of Hamilton, Ontario, it is easily distinguished by the greater 

 slenderness of its branches and branchlets and the longer and less over- 

 lapping thecae, which in the Niagaran form number 20 in 10 mm. 



Fig. 54 Ptilograptus hartnageli 

 sp. nov. Enlargement (x 10) of type speci- 

 men 



