48 



depressed in tlie interradial areas. The plates are all nodose or 

 subspinous. The column i.s round, radiately furrowed and jjioreed 

 by a large cinque foil columnar canal. 



The baeals are of equal size, have an hexagonal outline and form, 

 a nodose rim around the end of the column. First radials bear a 

 high, transverse, sharp node. Second radials, short, wide, quad- 

 rangular. Third radials pentagonal, small ; three of them bear upon 

 each of the upper sloping sides, three secondary radials giving two 

 arms to each of the three rays. The other two rays adjoin the 

 a/.ygous area and the most distant sloping sides of the third 

 radials bear three secondary radials and the proximal sloping sides 

 bear a tertiary radial which is axillary and bears upon each of the 

 upper sloping sides three tertiary radials, which gives to each of 

 these rays three arms. There are, therefore, twelve arms in this 

 species and twelve ambulacral openings to the vault. 



The first regular interradials rest between the upper sloping 

 sides of the first radials and separate the second and third primary 

 and first secondary radials. Each of these plates beai-s a very large 

 node and is followed by a single plate which in turn is followed 

 by two plates that connect with the plates of the vault. The first 

 azygous plate is in line with the first radials and is followed by 

 three plates in the second range, two in the third range and two 

 in the fourth range that connect with the plates of the vault. 



The vault is somewhat couoidal, remarkably large, and covered 

 with convex, tumid and subspinous plates. 



Found in the Warsaw Group, in Tennes.see, and now in the col- 

 lection of Wm. F. E. Gurley. 



DORVCKINUS OKEENEI, n. sp. 



]'/i(t(' I ', Fid. ] , hti.siil riciv; Fi g. ii, a.zijgouK k'kIi' rioir, injiiri'il 



in I lie. rr^inii of Ihc opening; Fig. •>, HHiinnit view, 



sh.iiiring the l)rol<ci) bitlb over the nzygoits .■<ide 



(iiid part of flic plufes over two raija. 



Species large and robust. Calyx rudely pentagonal in outline, 

 by reason of the elevated radial ridges; broadly truncated below for 

 the attachment of a large column; breadth two and a half times as 

 much as the height to the base of the arms; plates very thick and 

 more or less convex; radial ridges, increasing in convexity as far 

 the third primary radials, the upper parts of which are directed 

 nearly horizontally; sutures beveled; surface sculptured. 



