Plate 2. 



Page. 

 HADROCRINUS DISCUS Lyon 9 



Fig. 1. Dorsal view of a s])e<'imen obtained since Lyon's time, showing all 

 cliaracters better than the type, namely, the shallow base, with 

 minute notches at the corners of the radials indicating the remnants 

 of atrophied basals; radials indented by the large stem-lumen, and 

 marked by striae (not clearly reproduced in the printed figure) of 

 the huge column facet which enveloped them; distribution of pits 

 upon the calyx plates; and the beginnings of the heavy, biserial arms. 

 Slightly imder natural size. (See also text figs. 3 and 4.) 

 Onondaga: Louisville, Kentucky. 



HIMEROCRINUS PLENISSIMUS (Lyon) 



2. Unretouched photograph of a specimen minus the basals; to show the 



intense sculpturing by grooves and ridges which obscures the suture 

 lines. 



Onondaga: Louisville, Kentucky. 



MARSIPOCRINUS STRIATUS Wachsmuth and Springer 



3. Detail of part of tegmen of specimen from which the diagram, figure 10, 



Plate 1, was made, showing the am])idacra and the pinnule openings 

 to which they lead. X2. Silurian: Tennes.see. 



MARSIPOCRINUS TENNESSEENSIS Roemer 



4. Detail of part of tegmen with the pinnules themselves in position, both 



from the free brachials and from the interrays, corresponding to the 

 openmgs in Comar.thocrinvs and Dolatocrutus. X2. Silurian: Ten- 

 nessee. 

 (Both the last from the author's paper on Scyphoerinus, Plate 9.) 



61 



