448 THE CEINOIDEA CAMEEATA OF NOETH AMEEICA. 



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, Iowa. 



Type in the Washington University Museum at St. Louis. 



Macrocrinus carica (Hall). 

 Flafe XXXVII. Fig. 8. 



1861. Actinocritiits carica — Hail; Prelim, Descr. New Crin., p. 10. 



1873. Batocriuus {Eretmocriiius) carica; Meek and Worthen ; Geol. Kep. IlliEois, Vol. Y., p. 368. 



1877. Batocriuus carica — S. A. Miller ; Amer. Pateoz. Foss., p. 71. 



1881. Hretmocriitiis carica — W. and Sp. ; Re-vision Palffiocr., Part II., p. 172 (Proceed. Acad. Nat. Sci. 



Pliila., p. 3i6). 

 1890. Eretmocriims carica — S. A. Miller; 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 

 shghtly 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 joints 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- 

 ano^ular, longer than the first, and somewhat wider. Distichals 3 X 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. 



