94 OWEN AND SHUMARD'S FOSSIL CRINOIDEA. 



The basal plate of the genus Synhathocrinus is described by Austin as being 

 undivided. (Monograph Recent and Fossil Crinoidea, page 93.) We are convinced, 

 however, from an examination of numerous specimens from Kentucky, Indiana, Iowa 

 and Tennessee, that this is an error. In all well preserved specimens we have found 

 the basal plate to consist of three pieces. 



This species resembles in some respects Synhathocrinus conicus, (Phillips,) but is 

 easily distinguished by the larger size of its basal plate, and the shortness of its 

 superior plates. From the description of Synhathocrinus Tennessee^, (Troost in MS.) 

 it differs in several important characters, and occupies a different geological position. 



EXPLANATION OF FIGURES. 

 Fig. 7. a. Basal view, showing the tripartite character of the basal plate. 



« b. View of the side exhibiting the dental elevations on the superior edges of the arm-bearing plates. 



