Contributed by Andrew Smith, November 2011
| Classification and/or Status | Nomen null.; misspelling of Xystria Pomel, 1883 |
|---|---|
| Remarks | Kier, P. M. 1966. Noncidaroid Paleozoic echinoids. Pp. U298-U312 in R. C. Moore (ed.) Treatise on Invertebrate Paleontology. Part U, Echinodermata 3. Geological Society of America and University of Kansas, Boulder. |