. Ss ai : 
SL A RE Ee SS 
BATOCRINID.&. 939 
which decrease in size upwards. Interdistichals one or two, placed longitudi- 
nally. Ventral disk hemispherical; the plates nearly flat and of irregular 
arrangement; orals and radial dome plates a little larger and convex. 
Anus subcentral. Column strong, the axial canal large and obtusely pen- 
tangular. 
florizon and Locahty. — Hamilton group, New Buffalo, Iowa. 
Megistocrinus Farnsworthi (Wurt). 
Plate XLVITT. Figs. Aa, b. 
1876. Wuuite; Proceed. Acad. Nat. Sci. Phila., p. 29. 
1881. W. and Sp.; Revision Paleoer., Part II., p. 138. 
Of moderate size. Calyx subglobose, nearly as high as wide; the lower 
portions of the dorsal cup to the middle of the first costals truncated, the 
sides almost at right angles with the base, very slightly expanding to the 
arm bases, the latter somewhat projecting; the plates convex and without 
ornamentation. 
Basal disk proportionally large, slightly- projecting; the central part 
a little excavated for the reception of the column; axial canal rather large 
and obtusely pentangular. Radials horizontal, smaller than the costals. 
First costals abruptly curved; the lower end of the plates on a level with the 
radials, the upper: ends vertical. Distichals three in the two antero-lateral 
rays; in the three other rays but one, which being axillary is succeeded by 
24 palmars. Arms sixteen, arranged in groups of two and four; the arm 
bases a little projecting. Interbrachials: 1, 2, 2, 3, followed by several 
smaller pieces between the arm bases. The first anal plate, which is a little 
narrower than the radials, succeeded by rows of three, four, and six pieces, 
with numerous irregularly arranged plates above. Interdistichals two to four, 
the lower one sometimes touching the costal axillary. Ventral disk high, 
slightly conical; composed of rather large pieces. Orals completely isolated 
by supplementary pieces; they are larger than the surrounding plates, but 
not more prominent., Anus subcentral. 
Horizon and Locality. — Hamilton group ; Solon, Towa. 
Types in the Museum of the State University at Iowa City. 
