In the comments, James Trager brings to our attention his recent synonymy of the venerable Formica nitidiventris with Formica pallidefulva. This is one of the most common ants, and in my opinion one of the prettiest, in eastern North America. Many of us from the east learned of this ubiquitous species incorrectly as F. nitidiventris, so the synonymy may take some getting used to. In any case, the name nitidiventris is sunk, so you’ll only make yourself look obsolete if you persist in using it.
The Trager et al (2007) revision of the Formica pallidefulva group is excellent, by the way. Thorough and well-illustrated. I had no troubles sorting out the ants in my collection, which turned out to contain all five of the group’s species.
source: Trager, J. C., J. A. MacGown and M. D. Trager. 2007. Revision of the Nearctic endemic Formica pallidefulva group, pp 610-636. In Snelling, R. R., B. L. Fisher, and P. S. Ward (eds) Advances in ant systematics (Hymenoptera: Formicidae): homage to E. O. Wilson – 50 years of contributions. Memoirs of the American Entomological Institute, 80.