2T4 
SMITHSONIAN INSTITUTION 
PLATE 21 
(Figures natural size unless otherwise noted) 
Pycnosaccus patei Springer 
Fig. I. Complete crown with part of stem; r. ant. view. 
la. Posterior view of same, showing anal and radianal plates. RA in oblique position. 
lb. An interradius, filled by an integument of small plates.' X 2. 
2. Another crown, showing arms more fully, and the interradial integument. 
2a. The integument enlarged. X 2. 
3. 3a. Anterior and dorsal views of specimen with very sharp ridges. 
4. 'Very large crown, with distal ends of arms curving down into the interradial spaces. 
Beech River formation; Decatur County, Tennessee. 
P.\GE 
. 67 
Pycnosaccus welleri Springer 67 
Fig. 5. Flattened crown with long stem; anterior view; has 3 and 4 IBr. 
5a, sb. L. post, view of crown of same, and restoration in outline of natural contour. 
6. Crown with part of stem, ant. view. 
6a, 6b. Posterior and basal views of same. 
7. Larger crown, flattened, with stem ; a small calyx and long arms, 2 and 3 IBB. 
Beech River formation; Decatur County, Tennessee. 
Pycnosaccus laurelianus new species 67 
Figs. 8, 8a. Anterior and posterior views of complete crown. X 2. 
Laurel limestone; St. Paul, Indiana. 
( ?)Pycnosaccus dubius Springer 68 
Crown with plates displaced, and complete stem tapering to very long and slender 
columnals. 
Probable arrangement of calyx plates. 
Beech River formation; Decatur County, Tennessee. 
Clidochirus americanus Springer 69 
Figs. 10, loa. Anterior and posterior views of crown, showing small RA at foot of r. post. ray. 
II. Another specimen with long stem; r. post, view, showing same small RA. 
Clinton group; Dayton, Ohio. 
.'Ml figures on this plate, except 8 and 8a, are taken from the author’s work on the 
Crinoidea Flexibilia, 1920. 
Fig. 9. 
9a. 
