68 SMITHSONIAN INSTITUTION 



PLATE VI 

 (All figures natural size unless otherwise stated) PAGE 



Scyphocrinus pratteni (McChesney) 50 



Fig. 1. The holotype, showing base and lower part of calyx, formerly in the Chicago 

 Academy of Science, destroyed by fire in 1870. Left anterior radial 

 view ; drawn from a sulphur cast of the original made by Whitfield, 

 now in the author's collection. 



Tennessee River, Northern Alabama. 



2a. A large distorted calyx with rays to IIBr 7 , from posterior interradius. 



2&. Basal view of same; r. post. iR upward; shows the protuberant iBr areas. 



2c. Restoration of same, from r. post. R, to show the natural contour, and the 



course of the fixed pinnules ; iBr and iP from IIBr up marked by 



diagonal hachure. Lower part of radial series not shown sufficiently 



depressed. 



Helderbergian. Hardin County, Tennessee. 



Scyphocrinus mutabilis n. sp 47 



3a. Lateral view of eroded calyx from 1. ant. iR ; base restored from other 



specimens. 

 3&. Basal view of same ; post. iR upward. 



(See more characteristic specimens on PI. VIII.) 

 4. Fragment showing base ; 1. ant. iR upward. 



Perry County, Tennessee. 

 $a-d. Detached fragments of calyx, not known to be from the same individual, 



arranged in natural order ; to show sculpturing of plates. 

 Se. Part of ramus above axillary IIBr from a larger individual. 

 6, 7. Detached bases, to show costae and grooves at margin of plates. 

 8, 9. Plates of interbrachial areas, to show sculpturing. 



10-14. Separate plate showing surface sculpturing in different parts of the calyx. 

 15, 16. Edges of lower calyx plates, showing grooves or folds upon the margin, 

 but not penetrating the plates. 



17. Similar view of plate enlarged. X 2. 



18, 19. Inner floor of plates from different parts of the calyx, showing the 



sculpturing on the inner surface. 



Helderbergian. Benton County, Tennessee. 



