Fig. 5. Protasterina flexuosa (Miller and Dyer, 1878), Upper Ordovician of the Cincinnati region (see Appendix 1 for details). A. Previously unfigured specimen of the original suite of specimens described by Ulrich (1878); CMC 25002, ventral. B. Previously unfigured specimen of the original suite of specimens described by Ulrich (1878); CMC 25003, ventral. C. Another specimen that was possibly part of the original suite described by Ulrich (1878); MCZ 108086, ventral. D. Several fragments (arrows) of Protasterina flexuosa preserved among crinoid stems and trilobite fragments, articulated crown of Ectenocrinus simplex (Hall, 1847) near center of slab, CMC P506354. E. CMC P50635; E1, two additional specimens, one dorsal (left), one ventral (right), trilobite fragment in lower right; E2, fine ribbing (arrow) preserved on distal articulation surface of ventral interambulacral muscle field; E3, stellate scales on dorsal surface of disk; E4, ventral surface of ambulacrals immediately outside the disk; E5, partial disarticulation exposed the triangular podial basin floor (arrow) and large interambulacral muscle gaps.