GRAPTOLITES OF NEW YORK, PART 2 3 I 9 



below] already in the Trenton shales; in forms corresponding to the typical 

 nicholsoni of Great Britain it does not appear until Utica time. 

 The National Museum contains slabs with tine specimens, obtained near 

 South Trenton, Oneida co., N. Y., about 6 to 10 inches above the 

 Trenton, according to a note by Dr Gurley. The)' are there associated 

 with Glossogr. (?) e u c h a r i s, Climacogr. t y p i c a 1 i s, Triar- 

 thrus b e c k i , L e p t o b o 1 u s i n s i g n i s and C o n u 1 a r i a p a p i 1 1 a t a. 

 Some of these specimens have been sent to Professor Lapworth by Dr 

 Gurley and been found by that authority not to differ from the typical 

 form [Gurley 1896, p. 72]. Other specimens in the same collection are 

 labeled as coming from the Utica shale of the Mohawk valley. The New 

 York State Museum contains a series of well preserved specimens from 

 a black shale at the east shore of Saratoga lake in Saratoga county, N. Y. 

 The shale occurs in an isolated outcrop and is not yet irrevocably deter- 

 mined as to its age. The presence of Glossogr. (?) eucharis, the 

 only associate of the Dicranograptus in this shale, would, however, also 

 point to its Utica age. Three well preserved fragments of this species 

 have been collected by Dr Ulrich in the "true Utica shale" at Cincinnati, O. 

 (the Dicranogr. ramosus of his list of 1880). 



In Great Britain D . nicholsoni is said to be very common, near 

 the top of the Glenkiln shales and in the Lower Hartfell shales, and to be 

 especially abundant and beautifully preserved in the zone of Climacograptus 

 wilsoni. Tullberg has also cited it from the zone with Nemagraptus gracilis 

 in the Middle Graptolite shales of Scania. 



Remarks. The careful description and illustration of this species in 

 the Monograph of British Graptolites permits a very close comparison 

 of our specimens with the British type material and this furnishes evidence 

 of slight, but constant differences. The most notable of these are the 

 smaller length of the biserial portion (here uniformly 5 mm), its smaller 

 width and the more slender and more convex form of the uniserial branches. 

 Also the axillary angles seem to vary between greater limits and to be 

 somewhat greater in the average. These differences are most uniformly 



