EXPLANATION OF PLATES. 



PLATE 54. PAGE 



ARACHNOCRINUS EXTENSUS, W. & Sp. Rowley. 180 



FIG. 1 — View of a calyx imbedded in the rock with its arms spread 

 out on the surface of the slab. 



MEGISTOCRINUS CIRCULUS? Rowley. 181 



FIGS. 2-3-4 — Side, dorsal and ventral views of a large specimen with 

 concave plates. 



MEGISTOCRINUS SPINOSULUS. Lyon. Rowley. 182 



FIGS. 5-6 — Basal and side view of a specimen from the Falls of the 

 Ohio. 



STEREOCRINUS ? INDIANENSIS, M. & G., Rowley. 182 



FIG. 7 — Basal view of a small imperfect calyx from the Hamilton 

 group at Speed's cement quarry, Clark county, Ind. 



FIG. 8 — Similar view of a somewhat larger, imperfect calyx, from 

 the Upper Helderberg group at the Falls of the Ohio, 



GENNAEOCRINUS SIMULANS, N. Sp. fRowIey.) 183 



FIGS. 9-11 — Side and basal views of a nearly perfect dorsal cup. 

 FIG. 10 — Basal view of another specimen, showing the same features 

 as in figure 11. 



BOTRYOCRINUS AMERICANUS, N. Sp. (Rowley.) 184 



FIGS. 12-13-14 — Basal, anterior and posterior side views of the type 

 specimen. 



