352 A. \V. GRABAU — SILURO-DEVONIC CONTACT JX NEW YollK 



A careful analysis of this rather meager fauna reveals the interesting 

 fact that in its individual species and in its ensemble it hears a striking 

 similarity to the fauna of the Coralline limestone of Schoharie county. 

 Trochocerds gebhardii, originally descrihed from the Coralline limestone, 

 is not otherwise known outside of it. This species lias heen found at 

 William sville hy the New York State Survey, and recently a very fine 

 specimen has heen found in the cement quarries at Buffalo hy Messrs 

 Vogt and Piper, of the Buffalo high school. 



Leperditia scalaris, the only crustacean so far obtained from the Man- 

 lius limestone of Erie county, is the representative of L.jonesi of the 

 Coralline limestone. Both are typical Silurian Leperditia) and related 

 to species occurring in the Niagara limestone. Among the brachiopods 

 of the Bullhead, Orthothetes hydratdicns and Spirifer eriensis have their 

 respective representatives in the Coralline limestone in Orthothetes inter- 

 striatus and Spirifer crispus var. corallinensis, nom. prop. This latter 

 variety differs from the normal S. crispus of the Niagara in its uniformly 

 obsolescent plications and angular mesial sinus, characters which most 

 strongly ally it to S. erier*sis. The typical Manlius limestone Spirifer, 

 S. vanuxemi, is much more closety related to the typical S. crispus than 

 to S. eriensis, which is its western representative, while, again, S. crispus 

 var. corallinensis has more points of resemblance to S. eriensis than to 

 the typical Niagaran & crispus. Orthothetes hydraulic us and Orthis {Or- 

 thothetes) inter str iotas are, as far as I have been able to compare them, 

 indistinguishable. 



Whitfieldella sulcata is a typical Manlius limestone species occurring 

 in that rock in central and eastern New York. It is not represented in 

 the Coralline limestone. W. rotandata (?) is represented by W. micleolata, 

 but W. beds (?) has no representative in the Coralline limestone. 



Westward extension of the Manlius limestone. — In Ohio the Manlius and 

 the Rondout limestones have not been differentiated. The two together 

 are known as the Waterlime, though not suitable for purposes of hydraulic 

 cement. The rock is in the main a compact magnesian limestone, chiefly 

 drab or brown in color, but occasionally becoming very light colored, 

 and again of a dark bluish color.* In the northwestern part of the State 

 the thickness is given by Orton as at least 600 feet, while in southern 

 Ohio the thickness is only 100 feet. "Throughout much of its extent 

 it is brecciated, the bed seeming to have been broken into sometimes 

 small and sometimes large angular fragments after their hardening, and 

 then to have been recemented without further disturbance.' 1 f 



* Orton, 1893, p. 15. 

 f < irton, loc. <-it. 



