74 SMITHSONIAN INSTITUTION 



PLATE IX 

 (All figures natural size unless otherwise stated) page 



SCYPHOCRINUS SPINIFER n. Sp 46 



Fig. la. The holotype as seen from the side originally exposed, showing a few 

 scattered spines on the weathered surface in the median area, and the 

 fringes of long spines at either margin, some of them forking, which 

 have been brought to view by cleaning. Note the parallel position of 

 the spines in each cluster, x f . 



ib. Opposite side of the specimen as exposed by cleaning, showing the sharply 

 sculptured plates and the numerous slender spines extending to the 

 region of the arm-bases ; many of them enlarging distally, some forking, 

 and others tapering to a point. Some are seen partially detached from 

 their sockets, xf. 



ic. Detail from same view as last, further enlarged, x 3. 



Helderbergian. Hardin County, Tennessee. 



Scyphocrinus ulrichi (Schuchert) 54 



20. Left posterior radial view of holotype ; a large, broadly ovoid specimen, 



with calyx intact to the lower IIIBr. The fixed pinnules are greatly 



modified, leaving little semblance of their primitive form. U. S. 

 National Museum. 



2b. Basal view of same ; 1. post. R upward. 



Helderbergian. Dougherty, Oklahoma. 



Scyphocrinus gibbosus n. sp 55 



30. Left anterior interradial view of holotype, an imperfect calyx preserved 



only to IIBr 5 . x f . 

 36. Basal view of same, post. iR upward; the basals, which were very small, 



are wanting, x f . 



Helderbergian. Franks, Oklahoma. 



Ptilosarcus brevicaulis Nutting 11 



4. Specimen of this Recent Pennatulid; for comparison, to show the form and 

 proportion of its bulbous root. No. 30057, U. S. National Museum. 



Tsiuka, Japan: 44 fathoms. 



Marsipocrinus tennesseensis (Roemer) 42 



5a. Complete tegmen with arms and pinnules attached ; r. ant. iR upward. 



5&. Detail of same enlarged ; parts of r. ant. and r. post, rays, showing the 

 regular brachial pinnules, and the interbrachial pinnules at either side 

 of the arms, with the ambulacra leading to them in the positions where 

 the pores are seen in text-fig. 19. x 3. 



Silurian. Decatur County, Tennessee. 



Marsipocrinus striatus? Wachsmuth and Springer 42 



6. Unretouched photograph of part of tegmen of specimen from which text- 

 fig. 19 was made, showing the ambulacra, and openings for fixed 

 pinnules. 



Silurian. Decatur County, Tennessee. 



