X 
— aes - 
BATOCRINID 4. 429 
rather large for the species, the nodal joints projecting and rounded at the 
edges, 
Ind., Keokuk, Iowa, and Pike Co., Mo. 
Type in the Hlinois State collection, Springfield. (The specimen figured 
on Plate XLVI. is the type of “ Batocrinus Gurleyi”’ R. and H.). 
Dizygocrinus montgomeryensis, var. unibrachiatus W. and Sp. (nov. var.). 
Plate XX XIII. Figs. 5, a, b, ¢. 
The above name is proposed for a form very similar to D. montgomeryensis, 
but having single arms in place of double ones. It also closely resembles 
D. biturbinatus ; but the specimens are larger, the dorsal cup is proportionally 
shorter, the arms are longer, less tapering, and placed farther apart. 
Horizon and Locality. — Associated with D. montgomeryensis in the Upper 
Keokuk beds, near Keokuk, Iowa. 
Types in the collection of Lisbon A. Cox, and Wachsmuth and Springer. 
Dizygocrinus mutabilis W. and Sp. (nov. spec.). 
Pigte XXXV. Figs. S, 9, 10, 711. 
Calyx biturbinate to subglobose ; the dorsal cup a little higher than the 
ventral disk ; the plates of the former flat, and the surface without ornamen- 
tation or other markings; suture lines slightly grooved. 
Basals forming a low basin, hexangular in outline. Radials fully twice as 
large as both costals together ; the upper face concave. First costals very 
short, linear, the sides convex ; the second pentangular with obtuse upper 
angle. Distichals larger than the costals, increasing in width upward. They 
are represented by two ranges of three plates in the anterior ray, and also in 
one of the divisions in the other four rays; while in the opposite division 
the second piece is axillary, and supports 2 X 2 palmars, thus giving rise to 
fourteen arm openings, which bear either single or double arms. Among 
our seven specimens there is but one in which all the arms are paired... In 
the six others the paired arms are indiscriminately intermingled with single 
ones, and in three of these specimens the right antero-lateral ray consists of 
two pairs, of which one pair rests over the suture line of two adjoining pal- 
mars and not upon a distichal. Arms rounded, long, incurving, and com- 
posed of rather long transverse pieces. Pinnules flat at the surface, their 
joints rather short. Regular interbrachials three. The anal plate is consid- 
Hlorizon and Locahty.— Upper part of Keokuk group, Crawfordsville, 
