598 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
convex. Orals separated by perisomic plates, and larger than the surround- 
ing pieces; the posterior one subcentral, wider than high; the others some- 
what larger and elongate. Covering pieces of first and second orders 
irregular, and difficult to distinguish from the superimposed interambulacrals, 
but those of the higher orders are regularly arranged in two rows. Anal ® 
tube nearly central. 
Horizon and Locality.— Transition bed between the Burlington and Keo- 
kuk groups. Pleasant Grove, Iowa, Nauvoo, Ills., and Canton, Washington 
Co., Ind. | 
ftemarks. — The specimen figured by Worthen as Actinocrinus lobatus 
Hall, in the Geological Report of Illinois, Vol. VIII., Plate XIL., Fig. 8, is 
a small example of Actinocrinus magnificus W. and Sp. 
Actinocrinus verrucosus Hatt. 
foie LIT, Figs. 2a, 6; ¢. 
1858. Hatt; Geol. Rep. Iowa, Vol. I., Part IT., p. 578, Plate 10, Figs. 7a, . 
Assia We ind Sp.; Revision Paleocr., Part II., p. 146. 
Syn. Actinocrinus asterias McCuEsney ; Descr. New Spec. of Foss., p. 13, and Trans. Chicago Acad. 
Nel, Voll; p.9, Plate 5, Hie. 6 
proportions of the calyx, the greater convexity of the plates, and their sur- 
| 
| 
Approaching in size the two preceding species, but differing widely in the 
face markings. Calyx distinctly lobed, its height from the base to the foot | 
of the anal tube about equal to the width at the ends of the brachial exten- | 
sions. The sides of the dorsal cup spreading uniformly to the top of the a 
first costals, thence abruptly outward, bringing the plates forming the 
brachial extensions into a strictly horizontal position. The plates between 
the lobes are raised slightly above the general surface of the plates be- 
low, forming a low rim around the upper margins of the dorsal cup, differ- 
ing in this from the two preceding species, in which this part is impressed, 
and the brachial appendages are more prominent. Tegmen almost as high 
as the dorsal cup; pyramidal, rising evenly from the outer margins of the 
lobes to the summit. Plates of the dorsal cup tumid, and the middle of the 
radials, first costals, anal plate, and first interbrachials, elevated into a promi- 
nent node, which, except on the interbrachials, is transversely disposed. 
From the nodes of the radials and anal plate sometimes two rounded ridges 
2 
a 
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