Published online by Cambridge University Press: 31 May 2012
Through the courtesy of Dr. S. Forbes I have recently had the opportunity of working over the Ephemerid material contained in the collection of the Illinois State Natural History Survey at Urbana, Ill. In this connection I offer the following descriptions of species which appear to be undescribed, as well as a note on a Mexican species, the identity of which has been doubtful.
* Contribution from the Division of Systematic Entomology, Entomological Branch, Dept. of Agric., Ottawa.