43 



EMPEROCRINUS INDIANENSIS, n. sp. 



Plate IV, Fig. 16, basal view; Fig. 17, azygous side view of the same 

 specimen, the plates on the vault are covered with the matrix. 



Calyx very low, saucer-shaped, truncated at the base or flat- 

 tened over the basal and subradial area, subpentagonal in outline. 

 Plates smooth or granular. Column round. Columnar canal 

 cinque foil. 



Basals consist of two plates of equal size and one much 

 smaller; together they form a flat pentagonal disc, which is al- 

 most covered by the end of the column. Subradials are of about 

 equal size, nearly as long as wide, three heptagonal, two hexag- 

 onal. First primary radials larger than the subradials, pentag- 

 onal, having two inferior sloping sides that rest between the 

 sloping sides of the subradials, abutting laterally upon the inter- 

 radials and being truncated entirely across the superior end. 

 Second primary radials of almost exactly the same size as the 

 first, but a little wider and turn the sloping sides in the opposite 

 direction, pentagonal, axillary, and support on the superior slop- 

 ing sides two secondary radials. This gives to the species ten 

 arms and ten ambulacral openings to the vault. The arms are di- 

 rected almost horizontally, but no part of them is preserved in 

 our specimen. 



There are three regular interradials in each area. The first one 

 truncates a subradial and separates the first and second primary 

 radials. It is followed by two plates that separate the first sec- 

 ondary radials and curve over and unite with the plates of the 

 vault. The azygous area is wider than the regular areas and con- 

 tains four plates. The first one is larger than a first regular in- 

 terradial, truncates a subradial and separates the first and second 

 primary radials. It is followed by three plates in the second 

 range that unite with the plates of the vault. 



The vault in our specimen is covered with the lime stone 

 matrix, so that the plates cannot be distinguished. 



Found in the Niagara Group at St. Paul, Indiana, and now in 

 the collection of Win. F. E. Gurley. 



