24 Trans. Acad. Sci. of St. Louis. 



Geological formation and locality : Lower Carbonifer- 

 ous, Hunsriickenwald, Elsass, Germany. 



b. Lepidesthes Meek and Worthen 1868.* 



Syn. Hybochinus Worthen and Miller 1883. t 



Test subspheroidal. Interambulacra composed of 6-7 

 columns of plates, imbricating aborally. Ambulacra very 

 wide, composed of ten columns of small plates, imbricating 

 adorally. Two pores to each ambulacral plate, placed cen- 

 trally. Surface covered with small granules. 



1. Lepidesthes colletti White. 



1878. Lepidesthes Colletti. White. Proc. Acad. Nat. Sci. 



Phil., p. 33. 

 1880. Lepidesthes colletti. White, Cont. to Inv. Pal. No. 



8, p. 163, pi. 40, figs. 2a-b. 

 1882. Lepidesthes colletti. White, 11th Rep. Geol. Surv. 



Ind., p. 362, pi. 41, figs. 2, 3. 

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



258. 



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

 vol. 2, p. 184. 



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

 vol. 7, p. 210. 



General form ovate. Interambulacra very narrow, com- 

 posed of four or five columns of small plates. Ambulacra 

 broad, composed of from eighteen to twenty rows of small 

 imbricating plates. Two round pores near the upper angle 

 of each ambulacral plate. Surface covered with small 

 granules. 



Geological formation and locality: Keokuk Group, Sa- 

 lem, Washington Co., Ind.; Crawfordsville, Ind. 



* Geol. Surv. 111., vol. 3, p. 522. 

 t Geol. Surv. 111., vol. 7, p. 331. 



