368 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 



Batocrinus icosidactylus Cassedat. 

 Plate XXYIl. Figs. 3a, I, c. 



1854. Batocrinus icosidactylus — Casseday; Zeitsclir. d. Deutscli. Geol. GesellscL., Vol. VI., p. 238, Plate 



2, Figs. 1, \a-c. 

 1857- Batocrinus icosidacii/lus — PicTET; Traitd de Palfont., Vol. IV., p. 324, Plate 101, Kg. 6. 

 1867. Actinocrinus {^Batocrinus) icosidactylus — M. and W. ; Geol. Kep. Illinois, Vol. V., p. 367. 

 1881. Batocrinus icosidactylus — W. and Sr. ; Revision PaliBocr., Part 11. , p. 166. 

 1885. Actinocrinus icosidactylus — Qcenstedt ; Haudb. der Petrefactenkunde (3te Anflage), Plate 77, 



Pig. 3. 

 1893. Batocrinus icosidactylus — S. A. Millek ; Adv. Sheets Geol. Rep. Indiana, p. 24, Plate 4, Figs. 1-5. 



Calyx nearly as wide as high. Dorsal cup rarely more than half the 

 height of ventral disli, low saucer-shaped, with a protuberant base; plates 

 heavy, slightly convex, their surface smooth or obscurely granular. 



Basal cup projecting conspicuously beyond the level of surrounding plates, 

 almost circular in outline ; the median jmrt deeply depressed for the recep- 

 tion of the column ; central perforation subpentangular. Eadials short, 

 partly hidden from view by the overhanging rim of the basals. First costals 

 quadrangular, three times as wide as long, narrower than the second. Disti- 

 chals two, a little larger than the costals. Palmars three, increa.sing in width 

 upward and placed in longitudinal series, which are separated by well defined 

 grooves. Arm openings facing laterally, forming a continuous row around 

 the calyx. Arms four to each ray ; their structure not known. Inter- 

 bracliials three (rarely four) to the interradius; the first much larger than 

 the other two. The anal plate, which resembles the radials, is followed by 

 three plates, and these by one or two. Interbrachials not connected with 

 the plates of the tegmen, the higher brachials being in lateral contact. 

 Ventral disk conical, passing gradually into a strong, almost central tube. 

 The larger plates, as a rule, are extended into thorn-like projections, and 

 are surrounded by smaller, slightly convex pieces. Orals quite excentric, 

 four of them spinous, the posterior one merely convex. The radial dome 

 plates, which are represented by plates of a first, second and third order, 

 are also spiniferous. Anal tube long, heavy, and composed of convex pieces, 

 among which larger thorn-like plates are scattered at intervals. Column 

 round. 



Horizon and Locality. — "Warsaw limestone ; Spergen Hills, Ind., and 

 Barren Co., Ky. 



