88 Brown — Silurian Limestone of Milesburg Gap. 



This limestone has been opened up at a number of places 

 along the ridge. Possibly some of these openings may have 

 been newly made when Rogers visited this region over fifty 

 years ago. At present they are concealed by a timber growth 

 and many of the trees growing in the quarry openings are at 

 least thirty years old and possibly much older. 



In one of these old openings high up on the hillside near the 

 end of the ridge, the limestone was observed passing upward 

 into a more shaly bed. From the weathered portions of this 

 shaly limestone a very rich ostracod fauna was obtained. In 

 addition to the ostracods only a single brachiopod and one 

 coral were found at this horizon. The following is a list of 

 the species identified : 



Cyathophyllum hydraulicum (Simpson). 



Whitfieldella nucleolata (Hall). 

 Leper ditia alta (Conrad). 

 Leperditia Altoides Weller. 

 Leperditia elongata Weller. 

 Leperditia gigantea Weller. 

 Leperditia jonesi Hall. 



The strata overlying this shaly limestone bed are apparently 

 shales, for they have weathered down to form the slight depres- 

 sion between this and the next limestone ridge. No outcrop 

 of these strata was observed. 



The next limestone ridge is also fossiliferous both w T here it 

 is exposed at the railroad track and higher up on the hill side. 

 No extensive collection was attempted at this horizon but 

 numerous specimens were found and every one that could be 

 identified was an Oriskany type, such as is found here in the 

 overlying white or yellow sandstone as well as in the Oriskany 

 of New York. The most abundant species were these : Spiri- 

 fer murehsioni, Leptocoelia Jlabellites, Rensselaeria ovoides, 

 Platyceras nodosus. It is evident then, that this upper lime- 

 stone is a part of the Oriskany. 



From the list of fossils given above it is also evident that 

 the lower limestone is much older and should be correlated 

 with the Decker Ferry while the overlying shaly bed contains 

 a fauna typical of the Rondout of New Jersey and eastern 

 New York. 



The object of this paper is twofold : first to show clearly 

 what the structure of this region is, and second, to definitely 

 place in the geological column the limestones which have been 

 mentioned. The accompanying diagram (fig. 1-B) will show 

 what the structure is, and when compared with Rogers' figure 

 (fig. 1-A) it can easily be seen where he was in error. The 

 lists of fossils given above show that the lower limestone hori- 



