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BATOCRINIDZ. 46] 
Arms in pairs, bifurcating on a minute axillary, which occupies the same 
face with the proximal arm plate; they are rounded and composed of rather 
short pieces, of which in the upper portions of the arms every third or 
fourth plate is extended laterally into a small node or short spine. Inter- 
brachials three; the first twice as large as the others, higher than wide, and 
with concave sides; the two of the second row long and narrow. Anal 
area distinctly rounded, forming a low longitudinal ridge, with a deep groove 
at each side. The first anal plate is generally a little narrower than the 
radials, and followed by a vertical row of three or four higher anals, quad- 
rangular in outline, which support a subcircular mammilloid protuberance 
containing the anus. Ventral disk highly convex, somewhat inflated ; the 
posterior oral and the first radial dome plates extended into long, slender 
spines, the former central, and surrounded in mature specimens by about 
eleven convex pieces of nearly equal size, among which the smaller orals, if 
represented at all, cannot be identified. Similar pieces surround the radial 
spines, which enclose secondary radial plates. Anus at midway between the 
central. spine and the arm regions; facing laterally. Column moderately 
small, composed near the calyx of narrow and wide pieces alternately 
arranged, 
Horizon and Locality. — Upper part of the Upper Burlington limestone, 
Burlington and Pleasant Grove, Iowa. 
Type in the (Worthen) Illinois State collection. 
Dorycrinus intermedius (M. and W.). 
INORG, Sig. Us 
1868. Dorycrinus quinquelobus, var. intermedius —MEEK and WortHEn; Proceed. Acad. Nat. Sci. Phila. 
p. 346, and Geol. Rep. Ilinois, Vol. V., p. 385; Plate 10, Fig. 4. 
Intermediate between Dorycrinus quinquelobus and D. nvississippiensis, dif- 
fering from the former in its larger size, the more abrupt spreading of the 
dorsal cup, the different form of the basals, and the much greater length of 
its spines; from the latter in having invariably but two arm openings in the 
antero-lateral rays; and from both of them in the enormous size of its 
column. 
Dorsal cup rapidly and uniformly spreading from the bottom of the radi- 
als to the arms; base broadly truncated, slightly projecting, and rounded at 
the lower margin ; the interradial spaces moderately depressed at the arm 
