190 
IOWA ACADEMY OP SCIENCES. 
Arch^eocidaris hallianus (Geinitz). 
JEocidaris hallianus Geinitz, 1866; Garb, nnd Dyas in Nebraska, 
p. 61, tab. V, figs. la-b. 
JEocidaris hallianus Meek, 1872; U. S. Geol. Sur. Nebraska, p. 
152, pi. vii, figs. 9n-d. 
Arclmocidaris hallianus, Keyes, 1894; Missouri Geol. Sur.,vol. 
IV, p. 129. 
A very small form, with spines about a centimeter in length. 
Horizon and localities. Upper Carboniferous, Upper Coal 
Measures: Kansas City, Missouri; Nebraska City, Nebraska. 
If the identification of the Kansas City specimen is correct, 
it seems probable that this form should more properly come 
under Archseocidaris than Eocidaris. 
Arch^ocidaris spinoclavatus Worthen & Miller. 
Archceocidaris und.. Meek & Worthen, 1873; Geol. Sur. Illi- 
nois, vol. V, pi. xxiv, figs. I3a-e. 
Archceocidaris spinoclavatus Worthen & Miller, 1883; Geol. Sur. 
Illinois, vol. VII, p. 337, pi. xxx, figs. 14a-c. 
Spines stout, enlarging and becoming triangular above the 
middle, spinules numerous, large. Interambulacral plates of 
moderate size. 
Horizon and localities. Carboniferous, Upper Coal Measures: 
St. Clair and Marshall counties, Illinois. 
Archa]OCIdaris dininnii White. 
Archceocidaris clininnii White, 1880; Proc. U. S. National 
Museum, vol. II, p. 260, pi. i, figs. 13-14. 
Arclmocidaris dininnii 1883; U. S. Geog. & Geol. Sur. 
Terr., 12th Ann. Rep., p. 131, pi. xxxv, figs. Qa-b. 
Archceocidaris dininnii Keyes, 1894; Missouri Geol. Sur., vol. IV, 
p. 130. 
Primary spines long, subfusiform, covered by long, scattered 
spinous jDrocesses. 
Horizon and localities. Upper Carboniferous, Upper Coal 
Measures: Kansas City, Missouri; Tecumseh, Nebraska; Red 
Oak, Iowa. 
Archa^ocidaris triserata Meek. 
Archceocidaris triserata Meek, 1872; U. S. Geol. Sur. Nebraska, 
p. I5I. 
Horizon and localities. Carboniferous, Upper Coal Measures: 
Nebraska City, Nebraska; Kansas City, Missouri. 
