_Gomphus viridifrons_ n. sp. Length of the abdomen about 33 mm., hind
wing about 27 mm.; black, face and occiput green; prothorax with
anterior margin and three spots green or yellow; thorax green with
spaces at base of wings, lateral suture and six bands before black,
the two middle bands are abbreviated anteriorly and separated by the
mid-dorsal carina which is very feebly green. Abdomen black, a dorsal
band and sides of first two or three segments yellowish, a yellow spot
at base of each of segments four to seven, and sides of eight and nine
usually yellowish.
Abdominal appendages of the male straight, about as long as the tenth
segment, from above, widest at base, gradually narrowed from apical
third and acute at apex; from the side prominently widened at base,
with a strong tooth beneath at two-thirds of the length. Hamules large,
of nearly the same width for the whole length and ending behind in a
hooked process. Vulvar scale almost as long as the ninth abdominal
segment, gradually narrowed, apical third divided and the two parts
divaricate.
Described from fourteen males and a female taken at Loudonville, Ohio,
June 14, 1900; and a male and female taken at Ohio Pile, Pa.—the latter
two specimens by E. B. Williamson.
The species averages larger than either _brevis_ or _abbreviatus_
and may be separated from the former readily by its green face, by
the striking differences in the vulvar lamina and by the hamules and
male appendages. In _brevis_ the tooth on the appendage is nearer
the end and the space from it to appex is noticeably curved while in
_viridifrons_ this space is practically straight.
It has more points in common with _abbreviatus_, but in that species
the vulvar scale is short and triangular, the hamules are smaller and
shorter, and the tooth on the superior appendage of the male is much
farther from the apex.
Through the kindness of Dr. Calvert and Mr. Williamson I have at my
disposal, specimens from which many of the accompanying drawings were
made. In _viridifrons_, _brevis_ and _abbreviatus_ I have made drawings
from different specimens of the same species to show slight variations.
This is _Gomphus_ sp. Williamson, Dragonflies of Indiana, 294.