LIBRARY

ODONATA 243
Superfamily LIBELLULOIDEA Satys 1840
A large group of well-known species commonly called skimmers because of
their sustained and continual flight over water. There are two families.
KEY TO FAMILIES
1. Triangle in fore wing with its upper side more than half the length ofthe
basal side; anal angle of the male wing usually angulate; posterior
margin of the eyes with slight projection; fore tibia of male with a
keel . CORDULIIDlE
Triangle in fore wing greatly widened so that the upper side is usually
less than half the length of the basal side; anal angle of the wing of
both sexes rounded; posterior margin of the eyes evenly rounded; fore
tibia of male without keel . LmELLULIDlE
Family CORDULIIDlE Banks 1892 (Cor'du-li'i-dre, from the Greek Kopo{iA1].
club; from the posterior enlargement of the abdomen).
A large family of strong.flying, often hrightly colored, dragonflies comprising
about 200 species. especially well represented in North America and Australia
but also widespread as indicated by the distribution of the following important
genera: Cordulia Leach (Holarctic), Somatochlora Selys (Holarctic and Austra·
lian), Macromia Rambur (almost cosmopolitan), Tetragoneuria Hagen (Nearetic).
In the largest genus, Somatochlora, North America is represented by 21 of
the 36 known species. They are mostly metallic blue and green species with
yellow stripes, spots, and bands and black legs.
Family LmELLULIDJE Stephens 1836 (Li'be1-lu'li-dre. perhaps from the
Latin libella, a level; in reference to the horizontal position of the wings),
Skimmers, Topers.
A large family of common, nonmetallic though b;rightly colored dragonflies,
whose abdomens are usually triangular in cross section and whose wings are
frequently partly clouded. The females are without a well· developed ovipositor.
There are approximately 570 species, widely distributed but more
abundant in the tropics than elsewhere. The important genera are: Libellula
Linn .• Leucorrkinz'o Brittinger, and Sympetrum Newman (Holarctic). Panta/a
Hagen (cosmopolitan). Tramea Hagen (eastern United States), Celithemis
Hagen (Nearctic), and Crocothemis Brauer (Ethiopian and Indo-Australian).
In Celitlzemis the wings are usually tinted brown or gold and rarely veined
red. The nymphs live in aquatic vegetation. Adults of the genus Li/Jellula are
called skimmers and are probably the best known of the dragonflies. The wings
are usually clouded in small or large areas. The nymphs are hairy and live in
the debris on the bottoms. The widow, L. luctuosa Burmeister. a blackish.
species 47 mm.long with broad dark basal wing bands, ranges over much of the
country east of the Rocky Mountains. The big red skimmer, L. saturata Uhler.