98 NEW YORK STATE MUSEUM 



daga limestone. This event belonged to the interval of the Helderbergian 

 and Oriskany deposition elsewhere in New York, and the filling of the 

 fissure is, doubtless, veritable Oriskany sediment. 



We have already observed that at various localities throughout western 

 and central New York the thin, cherty deposit of the Oriskany con- 

 tains fragments of the hydraulic limestone from beneath. This con- 

 dition was particularly noticeable in the remarkable section afforded by 

 the salt shaft put down at Livonia, Livingston co. Such organic re- 

 mains as occurred in this deposit were found entirely in the cement and 

 were not well preserved, but showed indications of having been worn 

 and broken by the waves. Evidence of this kind sufficiently demonstrates 

 an interval between the Manlius and Onondaga limestones unrecorded 

 in these sections, and shows the continuity of the rocks carrying the 

 fauna of the former with the sedimentation immediately preceding and 

 their discontinuity with the sedimentation of the true Helderbergian 

 period.* 



FAUNA OF THE MANLIUS LIMESTONE 



The species of the so-called "Tentaculite limestone", so far as 

 noticed, have been principally described in volume 3 of the Paleon- 

 tology of New York, and the citations given in that work are of 

 occurrences located mainly in the eastern and eastern-central parts of 

 the state. Even where the limestone is in immediate contact with 

 and conformable to the overlying deposits of the Helderbergian, there 

 are few evidences of the continuation of any well established species 

 above the " Tentaculite limestone " itself. In eastern-central New York 

 a repetition of the Manlius fauna may appear after a brief preliminary 

 invasion of the later and displacing fauna but in these oscillations be- 



'After writing this account of the physical disturbances in the strata at Buffalo, 

 based on observations made in 1899, I learned tiiat the phenomena had 

 also been studied by Dr A. W. Grabau, who has published the result of 

 his detailed investigations in a recent bulletin of the Geological society 

 of America (2 : 347-76, 1900. Siluro-Devonic contact in Erie county, N.Y.) 

 Grabau concludes that these fissures were formed by violent rupture of the 

 waterlimes before the incoming of the sandy sediment subsequently washed in 

 from above. 



