396 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
side, where the anal plate is followed by three and two pieces. Ventral disk 
higher than the dorsal cup, distinctly bulging at the anterior side, and hence 
shorter at the posterior. The plates flat and smooth, except the posterior 
oral which is sometimes slightly convex, and is strictly central in position. 
The ventral tube is excentric, bending obliquely upwards, so as to pass out 
frequently from between the arms. It is composed of thick, tumid pieces, 
heavy throughout, stoutest at midway, and obtusely pointed at the upper 
end, where there is a small aperture. Column small, the upper joint occu- 
pying but one third the width of the basal disk. 
Horizon and Locality.— Upper Burlington limestone; Burlington, Iowa, 
Henderson Co., Ills., and Sedalia, Mo. | 
Types in the (Worthen) Illinois State collection, and in the Museum of 
Comparative Zovlogy. 
fiemarks. — This species is readily distinguished by the bulging and 
asymmetrical form of the ventral disk, the stout, inflated and curving anal 
tube, and by the form of the arms, which widen more gradually than in 
any of the preceding species. 
Eretmocrinus calyculoides, var. nodosus W. and Sp. (nov. var.). 
Plate XXXIV. Figs. 6, 7, 8. 
The specimens for which we propose this variety differ from Hretmoerinus 
ealyculoides in having transverse angular nodes on all radial plates, and 
rounded nodes upon the interradial ones. Its general form is somewhat 
more elongate, less spreading near the arm bases, the radials are propor- 
tionally smaller, the ventral disk less bulging ; it generally has twenty arms, 
and these do not attain the same width in the flattened portions. In all 
other respects it agrees with the typical form. 
Horizon and Locatity.— Upper Burlington limestone; Pleasant Grove, Iowa. 
Types in the collection of Wachsmuth and Springer. 
Eretmocrinus matuta (Hatz). 
Plate XX XVII. Figs. Ga, b, c. 
1861. Actinocrinus matute— Hawi; Prelim. Descr. New Spec. Crin., p. 14. 
1873. Batocrinus (Hretmocrinus) matuta — Menx and WortHen 3; Geol. Rep. Illinois, Vol. V., p. 368. 
1881. Eretmocrinus matuta —W. and Sp.; Revision Paleoer., Part II., p. 173. 
Calyx small, subclavate, longer than wide. Dorsal cup once and a half 
as high as the ventral disk, expanding but little from the top of the basals 
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