AMERICAN SILURIAN CRINOIDS 
225 
PAGE 
Crotalocrinns cora (Hall) 129 
Fig. 17. Cast from an external mould showing surface markings, 3 ranges of calyx plates, and 
brachials within the radial facet. 
Racine dolomite; Chicago, Illinois. 
Crotalocrinus rugosus (J. S. Miller) 128, 129 
Calyx of a small specimen from Dudley, England; from anal side, showing characteristic 
sculpture. 
Detail of specimen from Gotland, showing arrangement of lower brachials at dorsal side. 
X2. 
Detail of ventral side, showing covering plates of ambulacra, and the mode of connection 
of arm-branches by small lateral processes with larger spaces between, forming a 
net-work admitting flexibility of the leaf-like radii. X 3- (Figures after Wachsmuth 
and Springer.) 
Wenlockian ; England and Sweden. 
Crotalocrinus pulcher (Hisinger) ....128,130 
Fig. 21. A nearly complete crown, with calyx injured by erosion, showing the radii in form of 
reticulate leaves which overlap each other. For comparison with the analogous rigid 
structures of Petalocrinus. 
Wenlockian; Gotland, Sv/eden. 
Fig. 18. 
19. 
20. 
% 
