442 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
are covered with conspicuous, transversely curved prominences, which are 
studded with two or three irregular nodes. First costals considerably 
smaller than the radials; the second smaller than the first, in some speci- 
mens pentagonal, in others trigonal. Distichals 2 X 2, larger than the cos- 
tals, especially the upper or axillary ones, which are almost as wide as the 
radials. Palmars 2 x 4, larger than the distichals. They support the arms 
invariably in three of the rays, but in the two posterior rays the second 
plate adjoining the anal side is frequently axillary and followed by postpal- 
mars. The distichals are not placed on a level with their fellows of the same 
ray, but are alternately arranged, and the same is the case with the two 
inner rows of palmars; the arm-bearing plates being placed horizontally. 
The brachials throughout the calyx are covered with elongate elevations, and 
these again by a row of small nodes. Arms twenty to twenty-two; their 
structure unknown. Interbrachials: 1, 2, 1, and 2 between the arms ; 
the first wider than long, its node transversely elongate; the two of the 
second range longer than wide, and the nodes disposed longitudinally. 
The anal plate, which is longer than the radials, followed by three plates 
— the two at the sides wider than the middle one — and by three irregular 
smaller pieces, which in turn support several rows of elongate interambula- 
crals. The plates of the tegmen increase in size as they approach the middle; 
they are heavy, proportionally large, and the centre of each is crowned with 
a small tubercle. The anal tube is almost central, stout, and apparently 
long. | 
fTorizon and Locality. — Keokuk group; Button Mould Knob, seven miles 
from Louisville, Ky. 
Types in the Yandell collection at Louisville, Ky. 
Lobocrinus longirostris (Hatz). 
Plate XXVIII. Figs. La-e. 
1858. Actenocrinus longirostris — Haut; Geol. Rep. Iowa, Vol. I., Part IT., p. 589, Plate 11, Figs. 4c, d, 
and 2. . 
1873. Batocrinus longirostris —Menx and WortHEN ; Geol. Rep. Illinois, Vol. V., p. 367. 
1881. Batocrinus longisrostris —W. and Sp.; Revision Palxocr., Part II., Oo. MOY 
Syn. Batocrinus cassedayanus — Murx and WortHeENn; Geol. Rep. Illinois, Vol. V., p. 370, 
Plate 5, Pigs. 17, 0: 
Of medium size. Calyx ovate, higher than wide; the dorsal cup higher 
than the ventral disk; the arm bases a little projecting. Plates more or less 
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