INDIANA PALAEONTOLOGY. J44. 



plate a little longer than broad. Above this are three very small elongate 

 pieces. 



An interrupted ridge crosses the first and second radial plates, being most 

 pronounced at the center of each plate and passing up the higher radials as 

 a mere central convexity. 



Numerous fine lines radiate from the center of each plate to that of the ad- 

 joining plate and by cross connecting lines give a fine pitted appearance to the 

 surface, in places, not unlike the ornamentation of D. excavatus, W. <k Sp. 



The suture lines are quite distinctly grooved so that no difficulty is exper- 

 ienced in tracing the plate outlines. 



The plates of the vault have the same pitted surface ornamentation as the 

 calyx and those along the ambulacral ridges and surrounding the base of the 

 anal tube have strong central spine-like nodes. 



There are twenty arm bases, four to the ray. 



This species may be compared with D. excavatus which has but two arm 

 bases to the ray and no ventral spines; D. major, W. & Sp., and D. Spinosus^ 

 M. & G., both smooth species, the latter, however, having twenty arms and 

 vault spines. 



The specific name is meant as a compliment to the Rev. H. Currie, of Thed- 

 ford, Ontario, an excellent collector in the Devonian of Canada. 



The type is from the Middle Devonian of the Falls of the Ohio and belongs 

 to the collection of Mr. G. K. Greene. 



Figure 3 is apparently of the same species, somewhat larger, with the same 

 number of arms but without the ventral disk in place. The basal funnel is 

 larger and deeper and the width of the calyx was, probably, greater in propor- 

 tion to the depth than in the type specimen. 



Figures 4 and 5 are of the same species but with greater depth in proportion to 

 the width, stronger ornamentation and deeper grooved suture lines. 



Two of the primary interradials are ten sided; two, eleven sided and one of 

 a doubtful number. 



The ornamentation, instead of radiate lines, seems to be pits and short, ever 

 changing, fine ridges. 



Figure 6 is a rather robust form in which two of the primary interradials 

 have ten sides and one, eleven. 



The ornamentation is injured in the weathered condition of the specimen, 

 but enough shows to indicate that it does not differ from the above described 

 specimens. It has twenty arms. 



The specimens represented by figures 1, 2, 3, 4, 5, 6, are all from the Mid- 

 dle Devonian at the Falls of the Ohio, and are the property of Mr. G. K. Greene. 



