116 



U.S. NATIONAL MUSEUM BULLETIN 262 



Plectoceras — Continued 



? rushense crebricinctum Girty 



Girty, G. H., 1911b: p. 144. 

 Syntypes (1 not located) 

 Wewoka Fm. 



120689 

 Oklahoma 



Girty, G. H., 1915a: p. 236, 237, pi. 27, figs. 11, 11a, b. 

 Syntypes (unfigured syntype 



not located) 120689 



Wewoka Fm. Oklahoma 



smithvillense Ulrich, Foerste, Miller, and Unklesbay 



Ulrich, E. O., et al., 1944: p. 86, 87, pi. 43, figs. 11-17. 

 Holotype and paratypes 109531-109533 



Smithville Fm. Arkansas 



sp. 



Ulrich, E. O., et al., 1944: p. 88, pi. 29, fig. 8. 



? sp. 



Miller, A. K., and Youngquist, Walter, 1948: p. 653, pi. 94, fig. 9. 



Figured specimen 113015 



Barnett Fm. Texas 



? spp. 



Gutschick, R. C, and Treckman, J. F., 1957: p. 1151, pi. 143, 

 figs. 3, 9-11. 



Figured specimens 136471-136473 



Rockford Ls. Indiana 



Probillingsites 



belli Miller, Youngquist, and Collinson 



Miller, A. K., et al., 1954: p. 109, pi. 54, figs. 1-10; text-fig. 14. 

 Holotype and paratypes 124619, 124588, 



124618a-d 

 Upper Ordovician Sh. Baffin Island, Canada 



