424 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
interradius consists of 1, 3, 2, and 2 plates. The ventral disk is hidden by 
the arms in all our specimens. Anal tube composed of flat piecés; it is 
rather stout and long, reaching to nearly an inch beyond the tips of the 
arms, and evidently was still longer. Column small, composed of thicker and 
thinner joints with rounded edges. 
Alorizon and Locality. — Keokuk group, Canton and Edwardsville, Ind. 
Types in the collection of Wachsmuth and Springer. 
ftemarks. — This species has its closest affinities with the preceding form, 
but is readily distinguished by its larger size, the more abrupt spreading of 
the dorsal cup, the greater length of the anal tube, its spatulate arms, and 
by having fourteen pairs of arms instead of sixteen. 
Dizygocrinus unionensis (Wortusry). 
Plate XXXV. Figs. 16, 17, 18, 19, 20. 
1884. Batocrinus unionensis —Wortnen ; Bull. LI. of Illinois State Museum, p. 26. 
1890. Batocrinus unionensis— WortHEN ; Geol. Rep. Illinois, Vol. VIII., p. 84, Plate 12, Figs. 5, 5a, 
and Plate 13, Fig. 3. 
Syn. Batocrinus pulchellus —§. A. Mitten; 1891, Adv. Sheets 17th Geol. Rep. Indiana, p. 68, Plate 
ll, Figs. 13 and 14. 
Syn. Batocrinus Davisi— Rowiey and Harn; 1891, Kansas City Scientist, p. 116, Plate 3, Fig. 9. 
Syn. (2) Actinocrinus Caroli — Hauu; 1860, Suppl. Geol. Rep. Iowa, p. 54. 
Of moderate size. Calyx depressed; the dorsal cup shorter than the 
ventral disk, almost saucer-shaped; the upper brachials placed nearly at 
right angles to the axis of the calyx. Plates slightly convex, covered with 
obscure granules, the median portions of the radials and costals marked by 
small transversely arranged nodes, which are confluent and form ridges. 
Suture lines more or less grooved. 
Basals short, annular, slightly projecting beyond the column. Radials 
twice or three times as wide as long, their upper faces concave. Costals as 
long as the radials but narrower; the first quadrangular, the second pentan- 
gular or heptangular. Distichals 2 X 2, followed by two rows of palmars, 
except in the anterior ray which has three successive distichals. Pal- 
mars and distichals of similar form, and as large as the costals. Arms 
single, generally eighteen, arranged at equal distances around the calyx; 
of moderate length, rounded on the back, and biserial from the second 
free plate. The two proximal arm plates quadrangular, somewhat wedge- 
shaped, and as large as the first palmars. Pinnules stout; their joints 
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