634 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
and their surfaces corrugated. Column rounded and stout; the nodal joints 
with undulated edges ; the axial canal moderately large and pentangular. 
Horizon and Locality. — Upper Burlington limestone ; Burlington, Iowa, 
and Quincy, Ills. 
Type in the (Worthen) Illinois State collection, Springfield. 
Teleiocrinus tenuiradiatus Hatt. 
Plate LIX. Figs. 5 and 6. 
1861. <Actinocrinus tenuiradiatus —HautL; Prelim. Descr. New Paleoz. Crin., p. 12. 
18738. Sérotocrinus tenuiradiatus — Merk and Woxrtuen; Geol. Rep. Lhimois, Vol. V., p. 349. 
1881. Teleiocrinus tenuiradiatus — W. and Sp.; Revision Paleocr., Part II., p. 149. 
A large species, remarkable for its broad rim, the great number of arms, 
and the flatness of the plates. Calyx urn-shaped, its height about equal to 
its greatest width. Dorsal cup to the base of the rim as long as wide, or 
longer, the sides slightly convex. The rim rapidly spreading from the top 
of the distichals, its outer margin at right angles to the axis of the calyx. 
Arm openings directed somewhat upwards. Plates very little convex, almost 
flat; the suture lines distinctly grooved. The plates are covered with nu- 
merous very fine and delicate strive passing from plate to plate; they are 
strongest at the sutures, where they form small pits at the intervening 
spaces; the plates are without nodes, and the ridges are generally less 
conspicuous toward the middle. 
Basals large, forming a cup, which spreads more rapidly than the radials 
and costals, and at midway is slightly constricted ; the lower margin sharply 
angular, and the bottom concave. Radials a little longer than wide, and 
more than twice as large as the costals, of which the first is hexangular, the 
second a little smaller, and heptangular. Distichals almost as large as the 
second costals. The palmars and succeeding brachials forming the rim grad- 
ually decrease in size upward, all being wider than long, and almost flat. 
There are from seven to eight bifurcations in each main division, or eighty 
to ninety arms to the species; they are very much crowded, and rounded on 
the back near the calyx; upper parts unknown. Regular interradials eleven 
to thirteen in five or six ranges, those of the upper row quite small. Anal 
plate somewhat narrower than the radials, succeeded by fifteen or sixteen 
plates. Ventral disk depressed above the rim, low-conical in the middle 
portions, the sides gradually passing into a large central tube. Plates of 
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