44 University Geological Survey of Kansas. 



above or below, hexagonal, in outline, by reason of the trun- 

 cated first radials, and the concave, wide azygous area.. Column 

 round. 



"Basals form a pentagon one-half wider than the column, 

 with a central, columnar cavity surrounded by an external rim, 

 for the support of the attaching column. Subradials of moder- 

 ate size, three of them apparently pentagonal, though as each 

 one abuts upon two basals, where there is an obscure angle, 

 they are really hexagonal. The two adjoining the azygous area 

 are heptagonal. They curve very slightly down to the basals, 

 and upward, toward the acute angles between the first radials. 

 They are not uniform in size or shape ; the heptagonal plate on 

 the right of the azygous area is the wider, and the one on the 

 left the longer one. First radials twice as wide as high, trun- 

 cated the entire width above, much thickened within, and sep- 

 arated from the second radials, on the outer face, by a gaping 

 suture, but immediately within a straight ridge extends from 

 one outer angle to the other, having a furrow on each side so 

 as to form a hinge on which the second plates articulate ; be- 

 hind this hinge, in the middle part of each plate, there is a 

 socket for the reception of a tooth-like projection. Second ra- 

 dials short and heavy and produced externally in a moderately 

 strong spine. 



" First azygous plate longer than wide, pentagonal, upper side 

 short, abutting below on a subradial and resting very slightly 

 oblique between another subradial and the under sloping side 

 of the first radial on the right. Second azygous plate longer 

 than wide, truncates a subradial, abuts upon the superior lat- 

 eral side of the first radial on the left, and the first and third 

 azygous plates on the right. Third azygous plate longer than 

 wide, truncates the first azygous plate, and abuts upon the su- 

 perior lateral side of the first radial on the right. The second 

 and third azygous plates are hexagonal, but the plates abutting 

 the superior side are not preserved in our specimens. A small 

 part of a proboscis is preserved in one of our specimens, that 

 shows some heavy, transversely furrowed plates. Other parts 

 not preserved. 



