14 Two specimens of nodose, constrictus-like species with distinctive form and ribbing. Compare var comprius. (2) Cast of AMNH. Cat. 24236, Cedar Cr. anticline, NW end, Gas City Dome Socy. S. of Glendive, a little W of center of TWSP 14 N, R55E, Dawson Co. About 1000 ft below top of Pierre. Strong widely spaced ventro-lateral nodes running on to septate whorls. Little vertical expansion and gradual lat. expansion on body chamber. Umbilical bulge - ribbing finer on or 1/2 BC but not as fine as D. yuc. (6) Spec. unknown loc. in CGS coll. - Bearpaw, Alta. Another comprius-like form, most BC missing. Broader umbilicus; from edge shoulder U.S. lies at about 2130 instead of 3 to 3:30. No forward arch of ribs ventr. See also Mceek V.9. pl. 25, fig 2 for similar, stouter, form. 15. S. pungens Smith, 1861 Spec. - Cobben Coll. Upper Bearpaw, Wolf Point Montana. CGS. 10375. - Bearpaw Fm., Belzger memb. 1/4 mile N. of confluence Davis Cr. + Frenchman River. Two specimens are similar in form 9