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IOWA ACADEMY OP SCIENCES. 
Lepidesthes coreyi Meek & Worthen. 
Lepidestlies coreyi Meek & Worthen, 1868; Geol. Sur. Illinois, vol. 
Ill, p. 525, fig. A. 
Ambulacra broad lanceolate, one and one-half times as wide 
as interambulacral fields; poral plates rather large, broadly 
hexagonal, in ten ranges. Interambulacral areas narrow with 
six to seven rows of plates. Surface granulose. 
Horizon and localities. Lower Carboniferous, Keokuk shales: 
Crawfordsville, Indiana. 
As remarked by Meek & Worthen, Lepidesthes with its 
imbricating ossicles bears the same relation to Melonites as 
Lepidechinus does to Archseocidaris. 
Lepidesthes colletti White. 
Leiyidestltes colletti'WYAie, 1878; Proc. Nat. Acad. Sci., Phila., p. 
33. 
Lepidesthes colletti White, 1883; U. S. Geol. Sur. Terr., 12th Ann. 
Rep., p. 163, pi. xl, figs. 2a-l). 
Like L. coreyi, but with very much narrower interambulacral 
areas. 
Horizon and loccdities. Carboniferous, Keokuk shales: Salem, 
Washington county, Indiana. 
Lepidesthes pormosus Miller. 
Lepidesthes formosus Miller, 1879; Jour. Cincinnati Soc. Nat. 
Hist., vol. II, p. 41. 
Horizon and localities. Carboniferous, Keokuk shales: Craw- 
fordsville, Indiana. 
Lepidesthes spectabilis Worthen & Miller. 
Hijbockinus spectahilis Worthen & Miller, 1883; Geol. Sur. Illi- 
nois, vol. VII, p. 332, pi. xxxi, figs. 3a-d. 
Similar to L. coreyi but smaller. 
Llorizon and localities. Carboniferous, Kaskaskia limestone: 
Prairie du Long creek, Monroe county, Illinois. 
Archbeocidaris drydenensis (Vanuxem). 
Echinus drydenensis Vanuxem, 1842; Geol. Rep. Third Dist., 
New York, p. 184. 
Archceocidaris drydenensis Shumard, 1865; Trans. St. Louis 
Acad. Sci., vol. I. 
Eocidaris drydenensis Hall, 1867; New York State Cab. Nat. 
Hist. , 20th Ann. Rep. , p. 298. 
