original description
Yen, T.-C. (1952). Molluscan Fauna of the Morrison Formation. <em>United States Geological Survey Professional Paper.</em> 233-B: 21-51.
page(s): 42, pl. 6, figs 11a-f [details] Available for editors [request]
From editor or global species database
Type locality "Locality 10, Sec. 25, T. 12 S., R. 101 W.; about 8 miles southwest of Grand Junction and 7/10 mile SE. of Blue Hills, on the north rim of Ladder Canyon, Mesa County, Colorado", United States [details]