Klem — Revision of the Palaeozoic Palae'echinoidea. 25 



2. Lepidesthes coreyi Meek and Worthen. 



1868. Lepidesthes Coreyi. Meek and Worthen, Geol. Surv. 

 111., vol. 3, p. 525, fig. A. 



1873. Lepidesthes Coreyi. Meek and Worthen, Geol. Surv. 

 111., vol. 5, pi. 16, figs. 2 a-b. 



1874. Lepidesthes Coreyi. Loven, Kongl. Svens. Vetens. 

 Akad. Handl., Bd. 11, no. 7, p. 42. 



1889. Lepidesthes coreyi. Miller, N. Amer. Geol. Pal., p. 

 258, fig. 350. 



1895. Lepidesthes coreyi. Keyes, Proc. Iowa Acad. Sci., 

 vol. 2, p. 184. 



1896. Lepidesthes coreyi. Jackson, Bull. Geol. Soc. Amer., 

 vol. 7, p. 209. 



General form subspheroidal. Interambulacra narrow, lan- 

 ceolate, slightly convex, composed of six or seven columns. 

 Ambulacra flat, broadly lanceolate and one and a half or twice 

 as wide as the interambulacra, composed of ten or eleven 

 columns of plates, all imbricating. Two small round pores 

 in the center. Surface covered with fine granules, from 

 eighteen to twenty-five to the larger interambulacral pieces. 



Geological formation and locality: Keokuk Group, Craw- 

 fordsville, Indiana. 



3. Lepidesthes formosus Miller. 



1879. Lepidesthes formosus. Miller, Journ. Cinn. Soc. Nat. 



Hist., vol. 2, p. 41, pi. 8, fig. 4. 

 1889. Lepidesthes formosus. Miller, N. Amer. Geol. Pal., 



p. 258. 



1895. Lepidesthes formosus. Keyes, Proc. Iowa Acad. Sci., 

 vol. 2, p. 184. 



1896. Lepidesthes formosus. Jackson, Bull. Geol. Soc. 

 Amer., vol. 7, p. 210. 



General form subspheroidal. Interambulacra composed of 

 five columns of plates, imbricating upward and outward. 

 Ambulacra occupied by eight or nine columns each of many 

 rhombic or irregularly hexagonal plates, imbricating down- 

 ward. Two pores in the center of each ambulacral piece. 



