J35. CONTRIBUTION TO 



The plate sutures are beveled and every plate outline can be seen at a. 

 glance. 



There are no central, nodes on the interradials but fifty or sixty sharp radi- 

 ating lines pass from the center of the first interradial to the adjoining plates^ 



Similar sharp lines also leave the center of the other calyx plates. 



Middle Devonian, Falls of the Ohio. Collection of Mr. G. K. Greene. 



M E G I S T O (J R I N U S O P P E L T I , N. Sp., ( Rowley) 



Plate 39. Fig. 5. 



The type specimen preserves only a part of the calyx but it is so diiferent. 

 from all other described species that we feel warranted in giving it a specific- 

 name. 



The basal plates form a convex hexagon. The central area occupied by 

 the column is broken through in the specimen here described. 



The fir-;t radials are large, and hexagonal, the length and width being equal.. 



The second radials are likewise hexagonal and with equal dimensions. 



The third radial is heptagonal and axillary, supporting on each upper 

 sloping side a somewhat smaller plate. 



The first anal plate is in the first radial ring and of about the same size as 

 tliese plates. 



Higher plates of the anal area can not be determined. 



The first interradials are nearly as large as the first radials, of equal length 

 and wudth, liexagonal. 



In the second line of interradials are two quite large plates resting on the 

 first interradial, one is six and the other seven sided, the length and breadth 

 being equal. 



Above these two plates are four hexagonal plutes, much smaller. Higher 

 plates are not present in the specimen. 



The ventral disk is unknown, also the number of arms. 



Each plate is convex with a spinous ventral node from which radiate to ad- 

 jacent plates, numerous strong raised lines. The convexity of the plates make 

 the plate sutures very plain. 



The ornamentation of this species is so difi'erent from all other species that 

 a comparison is not at all possible. 



The specific name is for the finder. Dr. Otto Oppelt, of New Albany, Ind.. 



Horizon, locality and collection, same as the last. 



