45 



Tlisals fonu ;i pcnt-a.ironiil disc, full one-halt' wider than llie 

 diameter of tlie fokunn. and having an lieniispherical depres 

 sion, for the attachment of the colomu, surrounded by a sinall 

 rounded rim. First primary radials nearly as lonj; as wide 

 and subequal in size. Second primary radials rather large, 

 quadrangular, and nearly as long as wide. Thii'd primary 

 radials very little, if any, larger than the second, wider than 

 long, iienta.gonal, axillary and in two of the lateral rays l;ear 

 upon each upper sloping side three secondary radials which 

 gives to each of these rays two arms. In the ray on each 

 side of the azygous area and in the ray opposite thereto, the 

 third primary radial supports, upon one upper sloping side 

 three secondary radials, and upon the other a single secondary 

 radial that is axillary and sujiports upon each upper slo])ing 

 side two tertiary radials, which arrangement gives to each of. 

 these rays three arms. Tliere are, therefore, thirteen arms, 

 in this species. In the ray on the left of the azygous area, 

 it is the proximal side of the third primary radial, that bears 

 the three secondary radials, and in the ray on tlu^ right it is 

 the distal side that bears tlie three secondarj' radials. 



The azygous area is substantially like the other int(Mradial 

 areas. The first interradials are the largest plates in the 

 calyx, have nine sides, and are broadly truncated above for 

 the second interradials. The second interradials are about or 

 more than half as large as the first, and are followed by a 

 single i^late in the third range full half as large as the second, 

 which unites with two elongated jjlates belonging to the vault. 



The vault is moderately convex, and correspondingly de- 

 pressed in the interradial areas toward the margin. It is 

 covered with a few rather large plates but the sutures are too 

 indistinct in our specimens for illustration. The plates ai(_' 

 granular but most of the granules are eroded, on our speci- 

 mens, so they are not shown in the illustration.. Each plate 

 over tiie junction of the arabulacral canals bears a strong cen 

 tial node. The azygous orifice is nearly central on the vault 

 and elevated but little above it. There is an ovarian a]ierture 

 on each side of eacli pair of arms and on each side of each single 

 arm close to the ambulacral openings which gives to this 

 species sixteen ovarian apertures. 



