380 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
rows of obscure nodes. Interbrachial plates three, consisting of a large tumid 
plate, followed by two small, slightly convex pieces, above which the three 
rows of palmars meet those from adjoining rays, except at the posterior side, 
where only the plates of the upper row are in contact.’ Anal plate longer 
than the radials; followed by three and three plates. Ventral disk de- 
pressed, greatly inflated above the arm bases; composed almost exclusively 
of the orals and radial dome plates, which are nodose. Anal tube compara- 
tively slender at the bottom, formed of convex, elongate pieces; its length 
not known. | 
Horizon and Locality. — Lower Burlington limestone; Burlington, Iowa. 
Types in the collection of Wachsmuth and Springer. 
Remarks. — This species in the construction of the calyx is closely allied 
to Batocrinus pistillus, and in the arm structure resembles some species of 
Lretmocrinus, 
Batocrinus clypeatus (Ha11). 
Plate XX VIL. Figs. Sa-e. 
1860. Actinocrinus clypeatus —Hatt; Suppl. Geol. Rep. Iowa, p. 12, Plate 3, Fig. 12. 
1867. Actinocrinus (Batocr.) clypeatus —Munx and Wortuen ; Geol. Rep. Illinois, Vol. IL., p. 150. 
1881. Batocrinus clypeatus— W. and Sr.; Revision Paleocr., Part IL., p- 166. 
Syn. Actinocrinus papillatus — Hat; Suppl. Geol. Rep. Iowa, p. 29, Photogr. plates (1872), Plate 
3.4, Figs: 10 and 11. 
Syn. Batocrinus papillatus —Mernx and WortuEn; Geol. Rep. Illinois, Vol. V., p. 367. 
Syn. Actinocrinus inornatus — Hatu; Suppl. Geol. Rep. Iowa, p. 24. 
Syn. Batocrinus inornatus — Mex and Wortuen; Geol. Rep. Illinois, Vol. V., p- 367; and 
Whitfield, Mem. Amer Mus, Nat. Hist., 1893, Vol. I., p- 15, Plate 2, Figs. 1-2. 
Syn. Batocrinus comparilis — 8. A. Miuipr, 1892; Adv. Sheets 18th Rep. Geol. Surv. Ind., p- 32, 
Plate 5, Figs. 18 to 20. . 
Syn. Batocrinus aspratilis Minter and Guruny, 1894; Geol. Surv. Illinois, Bull. 8, Plate 5, Figs. 
4, 5, 6. 
A very variable species. Calyx a little wider than long; the dorsal cup 
higher than the ventral disk, convex at the base, the sides concave. Plates 
from almost flat to moderately convex. 
Basals very small, in some cases invisible in a side view. Radials more 
prominent than any of the other plates, their median portions more or less 
tumid; they are wider than long and concave at the upper face. Costals 
quadrangular and pentangular, both together smaller than the radials ; the 
first smaller than the second. Distichals two, as large as the costals, each one 
supporting 2 X 2 palmars, which are in contact laterally and support the free 
arms. Arm openings twenty, arranged at almost equal distances, the inter- 
spaces slightly grooved. Arms very short, composed of two series of short 
a) 
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