INDIANA PALEONTOLOGY. J58. 



supports above three larger plates, the third series being composed of four 

 smaller ones, the two on the right directly below two arm bases. 



Here then are two arms that do not rest on a radial series, but shall we 

 say on interradial plates? 



This crinoid is not unsymmetrical so far as appearance goes. There is no 

 indication of injury that would have produced the anomalous character above 

 noticed, even in long continued growth. 



Directly above the anal ? area and below the base of the subcentral anal 

 tube is a slight protuberance, probably all that is left of an abortive ray. 



The radial series to the right of the abortive ray consists of four plates to 

 the bifurcation. . 



All of the dorsal plates have distinct central tubercles except the upper- 

 most of the interradial series. The radial nodes are connected by a low, sharp 

 ridge, and from node to node of the radial and interradial plates pass numerous 

 toothed lines and strings of small tubercles. A circular rounded elevation sur- 

 ■7»ounds the basal excavation. The ventral plates have central node-like tuber- 

 cles and small granular elevations. 



The character of the dorsal flattening is well shown in the illustration. 



The respiratory pores are not more than two to the arm base. 



The specimen is from the Upper Devonian, Speed's Cement Quarr\-. Clark 

 county, Indiana. 



DOLATOCRINUS GREEN EI, M. <fe G., Rowley. 



Plate 47. Figs. 4, 5, 6, 25. 



Miller & Gurley described the species with nineteen arms, as one of the 

 chief characters. The specimen under examination has but thirteen and yet it 

 can hardly be considered a new species. How unreliable even the number of 

 arms becomes as a specific character. The basal plates form a flat pentagon 

 with a central columnar pit. 



Three of the radial series have but one costal each, the remaining ones 

 having the normal two. In one of these abnormal rays, the bifurcating radial 

 supports on the right above, an interradial plate, making three plates to that 

 interradial series. 



A smaller radial plate rests on the left upper edge of this bifurcating first 

 costal and is itself a bifurcating plate. 



Perhaps our interpretation of this ray as a one-costalled series would not 

 meet the approval of some crinoid specialists. See figure 25. 



The absence of second costals in three of the rays, recalls Barris' genus 



