33 



and supports the third, which is three times as wide as high, 

 pentagonal, axillary, and supports upon the upper sloping sides 

 the secondary i-adials. 



In one of the secondary radial series there are three plates, in 

 six of them each has four plates, in two of them each has six 

 plates, and one of them has five plates. One ray which is opposite 

 the azygous area, having six secondary radials, supports upon 

 each upper sloping side tertiary radials, which continue to the 

 end of the arms. Nine other tertiary radial series do not bifur- 

 cate, but so far as can be determined all the others bifurcate 

 once, and one of the arms thus thrown off in each series bifurcates 

 again, except in one ray. This gives us eight arms in each of 

 four series, but only five arms in the ray opposite the azygous 

 side, which possesses three primary radials, thus making thirty- 

 seven arms in this species. But there is some injury to the 

 specimen in two or three places, and the last bifurcation may not 

 take place in one or two rays, and possiblj', therefore, the species 

 may have only thirty-six arms. 



The azygous area commences with one plate, sending a sharp 

 angle between the first radials to the angle of a subradial; this is 

 succeeded by three plates in the second range, and these by three 

 plates, and these again by two, the superior plate being the 

 largest in the area ' and acutely pointed above. There are, tliere- 

 fore, nine azygous plates. 



Found in the Kaskaskia Group, at Bowliug Green, Kentucky, 

 and now in the collection of Wm. F. E. Gurley. 



rOTERiOCBlNUS SCOrAE, Miller & Gurley. 



I'hdelH, Fio'. I, Jatercil rieir iiiKgniJiccl tiro d 'Koiiefer.s: Fig. J, 



liifernl view of s(t,m,e .tpcciitieii natiiraJ size, 



<tzy<JoiLS nre(( on the left. 



AVheu the authors described this species iu 1890 iu their "De- 

 scription of some new genera and species of Echiuodermata from 

 the Coal Measures and Subcarboniferous Rocks of Indiana, Mis- 

 souri and Iowa," which work was subsequently reprinted iu the 

 17tli Rej)ort of the Geological Survey of Indiana, only the azygous 

 side was illustrated, and, as it seemed desirable to have it further 

 illustrated, two lateral views are here presented, one natural size 

 and one magnified two diameters. 



—5 



