94. CONTRIBUTION TO 



The central opening of the vault is star-shaped and there, are five round 

 .•spiracular openings of which the anal opening is the largest. 



A cross section of the body is pentagonal, but not sharply so, the middle 

 of the interambulacral areas being slightly convex. 



Horizon, locality and collection same as the last. 



CODAS TER ATTENU ATUS, Var. robustus. N. Var. (Rowley.) 



Plate 30. Figs. 12, 13, 16, 17. 



The basal plates form a cone. The radial plates are narrow-elongate,, 

 forming nearly two-thirds of the entire length of the fossil. The ambulacra 

 are short and narrow and hardly seen on a side view. Crossing the four inter- 

 radial plates and the upper edges of the radials are, on either side of an am- 

 bulacrum, six or seven hydrospire slits starting from the interradial ridge and 

 running parallel with the ambulacra. 



The central opening is i-ound and rather small. 



The anal opening is round and much larger than the central opening. The 

 ends of the interradial ridges are broken, thus giving the appearance of open- 

 ings. 



The specimen is too badly preserved to show surface markings. 



The shape of this fossil, the short, narrow ambulacra and the rounded, 

 upper edges of the radials, together with the almost circular cross section sepa- 

 rates it at least as a variety from C atte)iuatu8. It will probably prove to 

 be a good species. 



Upper Devonian, Clark county Cement quarry, Clark county, Ind. Col- 

 lection of Mr. G. K. Greene. 



- C D A S T E R A T T E N U A T U S ? Lyon, Rowley. 



Plate 30, Figs. 14-15. 



This little blastoid differs somewhat from C. atfenuatus, but hardly 

 enough even to separate it from that species as a variety. The radials are so 

 tucked in above that the interradial spaces are small and the respiratory slits 

 seem to be few. The basal plates form a cone of half the body length, longer 

 proportionally than in ('. atteiiaatus. The entire body is conical in shape. 

 A section at the ends of the ambulacra gives a pentagonal outline. The am- 

 bulacra stands up sharply, while the interradial ridges are inconspicuous. 

 Again the horizon of this specimen is higher than that of C. attenuatus. 



Horizon, locality middle Devonian upper Helderburg group. Falls of Ohio. 

 Collection of G. K. Greene. 



