448 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
is long, stout at the base, but quite thin at the upper end. Column slender, 
the joints high. 
Horizon and Locality. — Lower part of the Upper Burlington limestone, 
Burlington, Lowa. 
Lype in the Washington University Museum at St. Louis. 
Macrocrinus carica (Hatt). 
Plate XXX VIL, Fig. 8. 
1861. <Actinocrinus carica — Hat; Prelim. Descr. New Crin., p. 10. 
1873. Batocrinus (Hretmocrinus) carica ; Mexx and Worruen ; Geol. Rep. Illinois, Vol. V., p. 368. 
1877. Batocrinus carica—S8. A. Mitter; Amer. Paleoz. Foss., evils 
1881. Hretmocrinus carica —W. and Sr.; Revision Paleocr., Part IL., p. 172 (Proceed. Acad. Nat. Sci. 
Phila., p. 346). 
1890. Hretmocrinus carica —S8. A. Mitter; North Amer. Geol. and Pal., p. 243. 
Larger than the preceding species, and more robust. Calyx longer than 
wide, ovoid; the dorsal cup one third to one half higher than the ventral 
disk. All principal plates of the calyx strongly nodose, the others flat or 
slightly convex; the suture lines obscure. 
Basals directed. downward, deeply notched at the sutures, and slightly at 
the middle of each plate, so as to form six angularities or small nodes at the 
lower end of the base; the bottom forming a deep concavity, containing 
several jomts of the column. Radials very large, wider than long, extended 
into a long transverse node which is directed obliquely downward. First 
costals small, almost linear, their surfaces flat ; the second are nodose, pent- 
angular, longer than the first, and somewhat wider. Distichals 3 < 2 in the 
three anterior rays; in the two posterior ones the divisions next to the anal 
side have only one distichal, which supports two palmars from each side; the 
other divisions have three distichals and no palmars, which gives twelve arms 
to the species. The distichals and palmars join laterally; the plates are flat, 
_ except the arm-bearing ones, which are rounded like arm plates and project 
outward. Arm facets a little concave, directed horizontally ; the ambulacral 
openings almost equidistant; the respiratory pores restricted to the inter- 
radial spaces. Structure of the arms not known. There is but one regular 
interbrachial plate, the anal side has three above the anal plate, all of which 
are strongly nodose. Ventral disk hemispherical, constructed almost exclu- 
sively of the orals and radial dome plates, which are large and tuberculous. 
There are at each interradius three or four interambulacral pieces, which are 
scarcely convex. Anal tube slightly excentric, rather slender, its length 
unknown. 
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