28 



Found by Geo. K. Greene, in whose honor the specific name is 

 given, in the Keokuk Group, at Edwardsville, Indiana, and now 

 in the collection of Wm. F. E. Gurley. 



CONULARIA SEDALIENSIS, n. Sp. 



Plate III, Fig. 4, fragment from the middle part of a specimen, 



somewhat twisted; Fig. 5, under side of the shell 



showing the nodes on the casta}. 



Species large, rather rapidly tapering, pyramidal, subi^uadrate, 

 in transverse section. We have several fragments of this species 

 that are twisted and curved in different directions, showing the 

 great flexibility of the shell itself. The specimen illustrated in 

 Fig. 4, presents the largest undisturbed surface of any of them. 

 The sides, as near as can be determined, are flat and equal. The 

 angles are not very deeply furrowed, and the longitudinal line in 

 the middle of each side is not very strongly marked. Surface 

 ornamented with wide, transverse, arching furrows that are separ- 

 ated by coarse cost.-P. In passing across the sides, the cost.-P 

 curves forward toward the aperture, and sometimes alternate at 

 the mesial line, and at other times cross it without apparent 

 interruption. The costiB are geniculated at the furrows, at the 

 four angles. The inner layer of the shell is of a light gray color 

 and differs very little in color from the limestone matrix; the 

 second or middle layer is of a reddish brown color and horny 

 texture. The cost® bear a line of strong tubercles which are so 

 fixed in the matrix that the shell is split and decorticated in re- 

 moving it from the matrix. The tubercles aud the middle layer 

 of the shell are broken away from the costfv on the specimen 

 illustrated by Fig. 4, but the second layer is preserved in many 

 of the furrows, where it is perfectly smooth. In some places, on 

 some of the specimens, the tubercules may be seen on the cosfao, 

 but they are best shown in the matrix after the shell is taken 

 out, as shown by figure 5. There are thirteen costie to an inch 

 in length, where a side is one and one-third inches wide, and 

 forty-two tubercles on one of the costiB in an inch in length. 



This species is distinguished by its wide transverse furrows, 

 coarse costte and strong, distant tubercles, without other orua- 

 moiitatioH. 



Found by R. A. Blair, in the Burlington Group, at Sedalia, 

 Missouri, and now in the collection of S. A. Miller. 



