MIDDLE MISSISSIPPIAN DISPARID CRINOIDS FROM THE MIDCONTINENTAL UNITED-STATES

Systematic restudy of Lower Mississippian disparid crinoids from the m idcontinental United States results in the recognition of nine valid s pecies and one left in open nomenclature. Although disparid crinoids a re not diverse, they may be locally abundant and be the dominant crino ids in certain settings. The following species are considered valid: C atillocrinus tennesseeae Shumard, Catillocrinus wachsmuthi (Meek and W orthen), Eucatillocrinus bradleyi (Meek and Worthen), Halysiocrinus br adleyi (Meek and Worthen), Halysiocrinus cumberlandensis new species, Halysiocrinus springeri Brewer, Halysiocrinus tunicatus (Hall), Synbat hocrinus blairi Miller, and Synbathocrinus swallovi Hall. Several spec ies are placed into synonymy. Catillocrinus shumardi Springer and C. t urbinatus are considered junior synonyms of C. tennesseeae. Halysiocin us granuliferus and H. perplexus are regarded as junior synonyms of H. tunicatus. Synbathocrinus angularis Miller and Gurley, S. granulatus (Wood), S. granuliferus Wetherby, S. robustus Shumard and S. troosti ( Wood) are deemed junior synonyms of S. swallovi. The youngest (Meramec ian) North American calceocrinids, Halysiocrinus sp., are reported, he rein, hem the Harrodsburg and Salem Limestones of Indiana.