88 



Basals form a narrow pentagonal rim almost obscured by the 

 column. Subradials abruptly bent upward and into the basal 

 concavity, at about the middle part, about as wide as long. The 

 one on the right of the azygous area heptagonal and broadly 

 truncated for the first radial, the next one to the right hexagonal. 

 First radials twice or more than twice as wide as high, pentagonal, 

 truncated the entire width above and separated from the second 

 radials by a gaping suture. Second radials larger than the first, 

 about twice as wide as high, pentagonal, prominent almost nodose 

 at the superior angle, and supporting on each upper sloping side 

 the secondary radials. There are six secondary radials in each 

 arm shown by our specimen, four of them are short plates with 

 transverse sutures, the first one is the larger one and the last 

 is pentagonal and supports upon each of the upper sloping sides 

 the tertiary radials. One of the arms does not again bifurcate 

 and consists of short flattened quadrangular plates. The other 

 arm bifurcates again on the eighth plate and the arm adjoining 

 the azygous side again bifurcates, and so does the corresponding 

 arm in the other ray, which gives us seven arms to each of these 

 rays. 



The first azygous plate is pentagonal, abuts upon two sub- 

 radials and the first radial on the right, and supports two inter- 

 radials in the second range, one of which truncates a subradial- 

 There are two interradials in the third range, beyond which they 

 are not shown in our specimen. 



It is not necessary to compare this species with any other for 

 the purpose of distinguishing it. 



Found in the Keokuk Group, at Salem, Indiana, and now in 

 the collection of Win. F. E. Gurley. 



ZEACKINUS CYLINDRICUS, n. sp. 



Plate III, Fig. 19, a large specimen compressed antero-pos- 

 teriorly showing azygous side; Fig. 20, a, smaller 

 specimen compressed laterally showing azy- 

 gous side ; Fig, opposite view of same. 



This species is rather large and very long. The body is sub- 

 cylindrical, though constricted above the calyx, slightly fusiform 

 in the middle part, and slowly tapering above. 



