The Isocolid Trilobites Cyphoniscus Salter, 1853 and Effnaspis Gen. Nov. in the Appalachian Region of Canada and U.S.A.
- 1 April 1972
- journal article
- Published by Canadian Science Publishing in Canadian Journal of Earth Sciences
- Vol. 9 (4), 415-421
- https://doi.org/10.1139/e72-033