  A simple $n$-vertex graph has a prime vertex labeling if the vertices can be
injectively labeled with the integers $1, 2, 3,\ldots, n$ such that adjacent
vertices have relatively prime labels. We will present previously unknown prime
vertex labelings for new families of graphs, all of which are special cases of
Seoud and Youssef's conjecture that all unicyclic graphs have a prime labeling.
