INDIANA PALEONTOLOGY. ii6. 



/*. nodosuH. See our figures 4, 5, 6, for the tendency toward extravagance in 

 this kind of development. Thus a variation in surface feature reaching ex- 

 travagance in development and becoming permanent, assumes a character of 

 specific importance. 



The diameter of a column of a very large P. ohf'><tii< is about three-six- 

 teenths of an inch, judging from the columnar scar on the basal plates-. 



The side pieces, pores and lancet plates will not be discussed in this con- 

 nection. 



The surface ornamentation is, doubtless fine lines, parallel with the piate 

 sutures as in other species of the genus, but the character of the surface pre- 

 servation in our specimen is not such as to show this. 



The specimen, figures 1, 2, 3, is from the Kaskaskia Limestone of Grayson 

 Springs, Ky., and was kindly presented to Mr. G. K, Greene by Dr. John V.. 

 Younglove, of Bowling Green, Ky. 



t 



P E N T RE M I T E S S U L C A T U S ? Roemer, Rowley. 



Plate 36. Figs. 4-5. 



The specimens figured are fragments of large Pentremites, exhibiting 

 many of the characters of P. obesus, but disagreeing in the less convexity of 

 the base, approaching more nearly to P. sulcatus in this particular. 



Figure 4 is a view of the visceral cavity, by the removal of one of the fork 

 pieces and the half of another adjoining. 



The interambulacral space is seen to be traversed longitudinally by two 

 folds that are received into a lunular pocket above, and the thickening of the 

 substance of the test below the middle of the body and the union of the sides of 

 opposite folds form deep pits beneath the ambulacra, to their distal ends-, 

 along the lateral margins of the ambulacra may be seen the lines of pores. 



The proportionate thickness of the test is also shown. 



Figure 5 shows the great depth of the anibulacral sulcus and the fluted 

 and folded character of the radial edges bounding the sulcus. 



Both specimens are from the Kaskaskia Limestone of Big Clifty, Hardin 

 county, Ky., and were collected by Mr. Charles Very, of New Albany, Ind. 

 They now belong to the cabinet of Mr. G. K. Greene. 



PENTREMITES CHEROKEUS? Troost, Rowley. 



Plate 36. Fig. 6. 

 Following Hall's description and figure in the old Iowa Report, we refer 



