ECHINODERMATA—CRINOIDEA. 



539 



129. M. nobilis Wachsmuth and Springer. (Fig. 1868.) 



Mississippic. 



Calyx subglobose, with height and width nearly equal. Basi- 

 radial sutures somewhat grooved. Arms in ten pairs. 



Kinderhook of Iowa. 



XLV. Genn^ocrinus Wachsmuth and Springer. 



Calyx deeply indented at the arm region. Plates thin, orna- 

 mented with radiating striae. B 3, small. R and costals similar. 



Fig. 1868. Megistocrinus nobilis^y^ 

 %. (After Wachsmuth and Springer. ) 



Fig. 1869. Gennceocrinus kentuckien- 

 sis, dissociated plates ; a, radial ; 6, costal 

 I ; c, costal 2 ; d, interradial. (After 

 Grabau. ) 



Costals six- and seven-sided. Above the distichals the branching 

 is from alternate sides, arms branching off from one side and 

 brachials of a higher order from the other. Arms eight. Tegmen 

 of small plates, rising but little above the dorsal cup and marked 

 with grooves and ridges. Anus excentric; no anal tube present. 

 Devonic. 



