EXPLANATION OF PLATES. 



PLf\TE 29.-C.)ntinued. PAGE 



FIG. 40. — Interior view of a specimen showing the 

 ambulaeral pores beneath the hydrjspire 

 folds, the latter broken away. 



FIG. 41. — A specimen with the test broken away be- 

 low, exposing the cast of the cavity and 

 the thickness of the test at the ambulac- 

 ral tips. 



PENTREMITES CONOIDEUS, Var. Perlongus, N. Var. (Rowley.) 87 



FIG. 28. — Side view of type, showing outline. 



PENTREMITES CONOIDEUS, Var. Amplus, N. Var, (Rowley.) 88 



FIGS. 31, 32, 33-34.— Side views of different indi- 

 viduals, showing outline. 



TRICOELOCRINUS WOODMANI, M. & W., Rowley. 90 



FIGS. 35-36. — Side and basal views of a specimen, 

 showing the triangular column and the 

 minute columnar perforation. 



FIGS. 42-43. — Side and basal view s of the triangular 

 column of another specimen. 



ORBITREMITES OPPELTI, N. Sp. (Rowley.) 86 



FIGS. 15-16. — Side and ventral views of the type 



specimen. 

 FIG. 17. — Another specimen consisting of an entire 



ambulacrum. 

 FIGS, 18, 19-20. — Side and summit views of this 



species in restoration. 



TALAROCRINUS SIMPLEX, Shumard, Rowley. 91 



FIG . 24,— Side view of a specimen with an extra ca- 

 lyx plate. 



FIGS . 25-26 — Side views of another specimen, hav- 

 ing two extra calyx plates. 



FIG . 27. — A normal specimen from the Keokuk lime- 

 stone. 



