COKALLINE LIMESTONE. 



325 



size of the minute cell is apparently the same as in S. concentrica ; and in such specimens as 

 break only vertically, there is no positive means of distinguishing this species beyond the un- 

 dulations of the laminae which correspond to the uneven surface. It seems indeed probable that 

 it may be only a variety of the S. concentrica., presenting this peculiarity in its mode of growth. 



Fig. 2 a. A portion of the surface of one of these masses, showing the nodose stellate laminae. 

 Fig. 2 b. An enlargement of the surface of two of these nodes. 



Position and locality. In the Coralline limestone at Schoharie. 



{Collection of John Gebhard juninr.) 



523. 1. STROMATOPORA CONCENTRICA. 



Pl. LXXIII. Fig. 2, 2 a, and 2 6. 

 See page 136, plate 37, fig. 1, of this volume. 



Masses of various forms, undistinguishable from this coral as it occurs at Lockport and else- 

 where in the Niagara group, are found in great numbers in this limestone at Schoharie. In 

 many cases where vertical sections are seen, the laminae are so regular that the nodose eleva- 

 tions of the preceding species can not exist, and we have therefore no visible characters to 

 distinguish it from S. concentrica. 



Fig. 2, 2 a, & 2 5. Individual masses of various forms. 



Position and locality. Coralline limestone at Schoharie. 



{Collection of John Gebhard junior.) 



Mr. Gebhard has discovered the Catenipora escharoides in the lower part of the drab- 

 colored limestone, which rests on the concretionary compact mass below, to which the term 

 Coralline limestone is applied. The same condition is true of the Catenipora found in Herkimer 

 county, where it appears to have continued its existence a short time after the commencement 

 of the argillaceous drab-colored deposit, though the coral itself is often connected with a nodule 

 or irregular fragment of more compact limestone, like the rock below ; and the same feature is 

 observed in the Schoharie specimen. 



