GRAPTOLITES OF NEW YORK, PART 2 



265 



convex), gradually increasing in width from .3 mm to about 1 mm, angle of 

 divergence 27o°-290". Axil wide, sicula small (1.3 mm) provided with a 

 small virgella. Four primary thecae approximately horizontal, bearing small 

 mucros. Thecae numbering 10 in 10 mm with slight variations (11 to 12 

 near center); overlapping about one half their length, inclined 15 ; the 

 ventral walls of the free portions of the thecae first straight, slightly convex 

 near the aperture ; the latter is slightly introverted, the excavation shallow. 



Position and localities. Walcott obtained the type of his description 

 from the Utica shale in the town of Trenton, Oneida co., N. Y. The State 

 Museum contains a slab from the type locality (Holland Patent, Oneida co., 

 N. Y.) bearing a great num- 

 ber of rhabdosomes in asso- 

 ciation with Triarthrus 

 b e c k i. We have nowhere 

 else observed it in the Utica 

 shale of New York and con- 

 sider it therefore a rare form. 



Dr Ulrich has sent me 

 two small fragments [see fig. 

 182] which he collected in the 

 "true Utica shale" at Cin- 

 cinnati, Ohio, and once had 

 cited with doubt as Graptolithus tenuis Portlock. They fully 

 agree with Walcott's species in their characters. Gurley has also listed the 

 form as doubtfully occurring in the Lower Dicellograptus zone of Arkansas 

 and in the lower Cincinnati beds. The Arkansas material to which he had 

 access is not in such a condition as to permit positive identification and the 

 reference to the lower Cincinnati is probably also based on the Ulrich 

 collection. 



Remarks. Walcott states that the form and proportion of the stipe are 

 similar to that of Graptolithus flaccidus Hall ; but that the thecae 

 are quite different. Close measurements of the dimensions of the branches 



Fig. 180-83 Leptograptus annectans (Walcott). Fig. i5o, 181 

 The sicular (reverse aspect) and distal portion of a specimen from the type 

 locality. Fig. 182, 183 Two fragments from the Utica shale of Cincinnati. 

 (Ulrich collection.) x 5 



