INDIANA PALEONTOLOGY. J54. 



of the radial plates to the arm bases, hardly noded at the plate centers. Low, 

 rounded radiating lines pass from plate center to the sutures, being most promi- 

 nent near the base. All of the radial plates are wider than long, and the same 

 is true of the interradial pieces, except the first, which is of equal dimensions. 

 The interradial ptate arrangement is 1, 1, 1, except the anal area which is 1, 1, 3. 

 Most of the plates of the ventral disk, especially those located ambulacrally, 

 have rather strong central nodes. The poor preservation of the ventral surface 

 prevents further diagnosis. 



The anal tube is nearly central and the inter-ambulacral areas are de- 

 pressed, making the arm lobes distinct. 



The arm formula is 2, 4, 3, 3, 3, or fifteen in all. 

 No respiratory pores (slits). 



The form is probably identical with M. & G.'s D. charlestowasnsisj differ- 

 ing mainly in its greater size and stronger ventral nodes. 



The artist has made the dorsal ornamentation in Figure 7 too much like 

 lines of nodes when in fact it is low, rounded radiating ridges. 



It is probable this form should be placed under D. preciosus as a variety, 

 since D. charlestownensis is hardly entitled to specific distinction. 



Horizon, locality and collection, same as the last. 



DOLATOCRINUS AMPLUS? M. & G,, Rowley. 



Plate 45. Figs. 10, 11, 12. 



This is a very depressed form, a broad concavity involving the dorsal 

 plates to the bottom of the third primary radials and the middle of the first in- 

 terradials. The columnar or basal funnel shallow. Stem rather small. 



All of the dorsal plates are strongly tumid, except tbe basals and first ra- 

 dials. Rather strong, sharp radiating ridges pass from plate center to plate 

 center. 



Each of the plates in the second series of radials is axillary. The first' ra- 

 dials are about as long as broad, the second and third wider than long. 

 The first interradials are scarcely longer than wide. 

 The ventral disk elevated but little. 

 Plates flat and ornamented by nodes or granules. 

 Inter-ambulacral areas scarcely depressed. 

 Anal tube rather small and sub-centrally located. 



