REVISION OF PALEOZOIC STELLEROIDEA. 137 



separated and wedged in bet^^een the adjoining four siipramarginal 

 ossicles. There appear to be 10 or 11 of these m a cohinm. On each 

 side of the radial columns in the proximal half of each ray are a number 

 of small accessory plates arranged in irregular columns. All of the 

 abactinal plates are more or less convex and bear numerous small 

 pustules clustered around a larger central one, all of which bore small 

 spines. 



Supramarginal plates very conspicuous, subquadrangular in out- 

 line, generally a little wider than long, Avith numerous small pustules, 

 among which toward each lateral edge is a large one upon which 

 probabh' articulated prominent spmes. Tliere are from 11 to 13 of 

 these plates in each colunm. In the distal third of a ray both 

 columns approximate and adjom each other closely. Each supra- 

 margmal plate Ues wholly and directly over an mframarginal and the 

 pieces appear as one consolidated plate with the abactinal side convex 

 and the actinal nearly flat. The supramarginals are the widest and 

 extend in part over the adambulacrals. 



Madreporite small, circular in outline, slightly convex and very 

 fuiely radially striated. It lies directly uj^on two basal supramar- 

 ginal plates of adjommg rays and directly outside of one of the large 

 interradial plates. 



An ocular plate termmates each ray. 



Inframarginals apparently like the supramarginals excepting 

 distally, where they are nearly tmce as long as mde. 



Adambulacral plates smaller than the inframarginals, nine in 

 the space occupied by five of the latter, somewhat -wader than long, 

 convex, and covered with numerous small pustules. 



Ambulacral grooves very narrow in the distal region. The ambu- 

 lacral plates appear to be as numerous as the adambulacrals, and are 

 H -shaped, with the podial openings between the plates m about the 

 mid-width of the column. 



AU other actinal characters are unknown, smce the two specimens 

 expose the abactinal area, though one has portions of the plates 

 removed, revealing the actinal characters described. 



Formnation and locality. — The ty}>e-specimen is in the Harris 

 collection of the United States National Museum, and another 

 specimen is in the Dyer collection of the Museum of Comparative 

 Zoology (No. 4). Both were found in the crinid beds of the Keokuk 

 group of the Lower Carboniferous at Crawfordsville, Indiana. 



Remarks. — There is no Carboniferous asterid with which Neo'pals&- 

 aster crawfordsvillensis can be confounded. 



Cat. No. G0607, U.S.N.M. 



