Both of these manuals are out of print. I have re-drawn gomphine appendages, showing the basic form of each species, including those described since 1955. Notes are included on identification and similar species, generalized habitat, distribution, and size. The gomphids are an interesting group of dragonflies. A few species are common, but most are uncommonly seen except by learning their habits and habitat, and searching for them at the right time.
Some species have brief flight periods, when they can be observed and captured.
A few species may be rare, such as Ophiogomphus edmundo , which was described in 1950, and was only known from type specimens until it was re-discovered in 1994. Some species are known to be common from the number of naiads and exuviae that may be collected, but flying adults are uncommonly observed. Some species may be completely absent from large sections of a particular river or stream, but may be regularly found at a particular riffle, rapid, or quiet pool. About a dozen new species have been described since 1975. About 42 species occur from Virginia to Maine.