856 NEW YORK STATE MUSEUM 



Mather in describing the rock series exposed at Rondout, Ulster 

 co. This formation, which is in typical section in Schoharie 

 county, as at Howes Cave and along the Cobleskill, is a dark 

 limestone abounding in corals and carrying a considerable fauna 

 besides, which has been described by Hall in volume 2 of the 

 Paleontology of New York. It is underlain in this section by 

 a mass of 30 to 50 feet of soft gray shales and, further east 

 along the Schoharie creek, this mass is lessened and the shale 

 is of greenish color. Professor Hall regarded this underlying 

 shale as pertaining to the Clinton formation, and, on account 

 of the stratigraphic position of the Coralline limestone and 

 because of the nature of its fossils, many of which he found to 

 be identical with or similar to known Niagara species, he con- 

 cluded, as above stated, that it was an eastern representative 

 of the Niagaran formation not otherwise known in this part of 

 New York State. The value of this determination has been 

 brought into question by several writers, specially as a more 

 careful study of the fauna of these beds indicates, notwithstand- 

 ing its affiliations to the Niagara fauna, specific identities of 

 notable importance with species which occur in higher horizons 

 in the State of New York. Thus we have observed that, above 

 the waterlime formations at the top of the Salina stage in 

 western New York, probably 1000 feet higher than the last 

 appearance of the Niagaran fauna, species occur which are 

 identical with the Coralline limestone species of eastern New 

 York, and these points of similarity have been quite clearly 

 pointed out in a recent publication by Prof. A. W. Grabau. 

 We have had previous occasion also to direct attention briefly 

 to the occurrence of a profuse development of a fauna similar 

 in many particulars, in a quite pure limestone interbedded be- 

 tween the upper and lower waterlimes of the Salina formation 

 at Frontenac island, Cayuga lake. Now, though the Coralline 

 limestone with its characteristic fossils appears in Schoharie 

 and Otsego county sections to lie below the waterlime forma- 

 tion as a whole, in the sections exposed at Kingston and 

 Rondout and early described by Lieutenant Mather in his report 

 on the geology of the first district, the formation and its fauna 

 apparently make a double appearance, lying at first below the 



