128 NEW YORK STATU MUSKUM 



Siirfari' snnH)lh, shiniug, Vjoaring only liue concentric lines. 

 Internal cast smooth. 



Dimnisious. liight 2ll nun; widlb across body whorl 17 mm; 

 liij^lit of ImkIv Nvhorl 18 mm. 



Locality. A':H)nia(ili' limestone, ^lanliiis. 



This very i>rctty s{KH'ie^ lias been fmiud by Prin. J. D. 

 Wilson of Syracuse, who has considerately presented the type 

 siHH-imen to the state museum. It is unlike any species known 

 from the New York Devonic in its short, concave spire and very 

 hir^e body whorl, features which will also distinguish it from 

 other forms of the genus. 



STRATIGRAPHY OF THE STAFFORD LIMESTONE 



This limestone has highly characteristic lithologic structure. 

 It i« when fresh of a dark chocolate brown, compact in texture 

 and incline'd to be splintery under the hammer. Its fossils, in 

 which it for the most part abounds, are often replaced by a black 

 crystalline calcite, and, when weathered, blocks of the rock 

 become gray, while the fossils are contrasted therewith by their 

 dark tint. From the meridian of Flint creek westward to Lake 

 Erie such blocks are common in the drift piles and are at once 

 recognizable. 



Along Flint creek is the first appearance of this interesting 

 limestone, but it is seldom that complete sections of the beds 

 are exi>osed anywhere in western New York. One was afforded 

 by the Livonia salt shaft, and another, fully described at <lie cnn- 

 clusion of this pai>er, occurs at Lancaster, Erie co. 



In the Livonia salt shaft, as recorded by D. D. Luther and the 

 writer in the 13th I'eport of the state geologist, the Marcellus 

 strata were regarded as beginning at a depth of 650 feet from the 

 surface and continuing downward to a depth of 866.5 feet, giving 

 the beds a thickness of 216.5 feet. This apparently great thick- 

 ness is due to the fact that, in the succession of the upper beds 

 which pass gradually into the Hamilton shales above, a consider- 

 able part of the blue black shales was assigned to this formation 

 on account of the preiK)nderance of Marcellus species. This 



