96 • NEW YORK STATE MUSEUM 



hydraulic, found between the base of the Onondaga or of the Oris- 

 kany sandstone when present, and the Eondout waterlimes lying 

 above the gypsum beds. These beds are the stratigraphic equivalent 

 of the Tentaculite limestone, for they contain species which charac- 

 terize this horizon in eastern New York, though Tentaculites itself 

 is rarely seen in the western exposures. 



At the quarries of the Buffalo cement co. at Buffalo, is a section 

 of unusual interest to which brief reference has been made. Above 

 the Rondout waterlimes the strata which bear the fauna of the Manlius 

 limestone are continuous to the base of the Onondaga limestone. 



The quarryraen divide this portion of the section into " cement 

 rock " below and " bullhead " above, and, though the lower passes 

 gradually into the upper, it is in the former (Rondout) that the species of 

 eurypterid crustaceans prevail, while in the latter fossils are not com- 

 mon, though the horizon is pretty well defined by an undescribed 

 species of Cyathophyllum with representatives of Whitfieldella 

 sulcata and Spirifer cf. vanuxemi (S, eriensis Grabau). 

 This " bullhead " waterlime occupies the position of and is coextensive with 

 the Manlius limestone and is the Manlius horizon. The upper surface of 

 this deposit is extremely uneven, and seldom conforms with the approxi- 

 mately parallel sedimentation lines of the rock itself. In parts of the 

 quarry, where this surface has been exposed on a large scale by the 

 stripping of the Onondaga limestone above, the contour is extremely 

 irregular, and the depressions in some cases take on the aspect of 

 crooked channels running into one another, the effect being just that 

 which would result from the probable cause, erosion before the deposi- 

 tion of the Onondasra limestone commenced. 



The horizon of the Oriskany sandstone is indicated only by a thin 

 seam of fine, bituminous matter, containing no sand except in a few 

 of the depressions mentioned, where small characteristic nodules of black 

 sand are found. 



In certain parts of this section the upper hydraulic or " bullhead " 

 strata show very positive evidence of disturbance and folding and at cer- 

 tain places the crest of these folds is seen to be partially removed, 



