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NEW YORK STATE MUSEUM 



and strikingly shown in the material from Saratoga lake ; but also apparent 

 in the specimens from Oneida county. On the other hand two of the frag- 

 ments from Cincinnati agree exactly with the description of the British 

 specimen in the length of the biserial section and its rapid widening to the 

 point of separation, while the third has the identical characters of the 

 Saratoga types in the biserial portion, which alone is retained. For this 

 reason we have thought it best to extend the description of D. nichol- 

 s o n i sufficiently to receive the latter form. 



a Dicranograptus nicholsoni var. parvangulus Gurley 



Plate 21, figure 2 



Dicranograptus nicholsoni var. parvangulus Gurley. Geol. Sur. Ark. An. 



Rep't. 1892. 3:417 

 Dicranograptus nicholsoni parvangulus Gurley. Jour. Geol. 1896. 4:73 



Dr Gurley has twice described, but not figured this well defined variety. 



We insert here his original (manuscript) drawings and add several other 



drawings of better preserved specimens from the Normanskill shale at Mt 



Moreno and Glenmont. In the last cited publication Gurley has drawn the 



following description of this variety from Stockport specimens : 



Proximal portion about 6 mm long ; at base 1 mm, and immediately 

 below bifurcation 1.5 mm wide ; with eight or nine thecae, each with a short, 

 sharp horizontal spine ; branches 1 mm wide, diverging at an angle of 35° or 

 40 (or thereabouts), often bending very slightly towards one another imme- 

 diately after the division, thus producing a slightly rounded, bulging appear- 

 ance. Thecae forming bent tubes, as in D. nicholsoni proper; as 

 nearly as possible 24 in 25 mm; those on the proximal portion and the first 

 few on the branches above the bifurcation spiniferous. On the branches 

 not more than three spiniferous thecae were seen. 



Position and localities. It was known to Gurley from the Lower Dicel- 



lograptus zone at Stockport, N. Y. and in Arkansas, and his Upper Dicello- 



graptus zone at Magog, Canada. We have also found it as the commonest 



graptolite in a layer of the Normanskill shale at Mt Moreno and likewise 



in fine specimens at Glenmont, below Albany. In the former place it is 



associated with L a s i o g r . m u c r n a t u s and D i p 1 ogr, I o 1 i - 



aceus; in the latter with Diplogr. foliaceus, Climacogr. 



