LIBRARY

196 COLLEGE ENTOMOLOGY
IMPORTANT ANATOMICAL CHARACTERS-Continued
External
Abdomen - regularly oval or nearly circular;
elongated or parallel-sided; usually
longer than head and thorax; tergite
I may be absent; eight- to IO-segmented.
SPiracles - five to six pairs on segments
II to VII, III to VII, or III to VIII.
GenitaUa - genital openings in an invagination
in the body wall.
Male - redeagus complex.
Female - not evident.
Cerci - absent.
KEY TO SUBORDERS
Internal
1. Maxillary palpi four-segmented; antennre normally four-segmented and
distinctly clubbed or capitate and concealed in a groove on the underside
of the headj mandibles horizontal; meso- and metathorax usu·
ally separated by a suture . . AMBLYCERA
2. Maxillary palpi absent; antennre three· or five-segmented, setifonn, not
concealed in a groovej mandibles verticalj meso- and metathorax
fused and without di'liding suture . .ISCHNOCERA p. 199
Suborder AMBLYCERA Kellogg 1896
(Am'bly-cer'·a, from the Greek nfl-13M,;, blunt, + Kepas, horn;
because of the presence of maxillary palpi?).
KEY TO FAMILIESl
1. All tarsi with two claws (infesting birds) . 2
Tarsi of middle and hind legs with one claw or nonej rarely two in forelegs;
some tarsi modified as hair claspers; labial palpi one-segmented
(infesting guinea pigs and other South American rodents) GYROPIDJE p. 197
2. Antennre capitate, five-segmented; legs long and slender; body clothed
with stiff, slender spines (infesting kangaroos, wallabies, and occasionally
dogs) . . BOOpnDlE p. 19&
Antennre clavate, four-segmented . 3
3. Prothorax and metathorax similar in size and shape, but inverted (infesting
Central and South American rodents). . TRIMENOPONIDlE p. 198
Prothorax and metathorax nonnal; meso- and metathorax fused or
separated by a suture. 4
1 There is little uniformity among entomologists in the classification of these confusing insects.
The total number of families varies from two to 10, and there is no agreement as to the
exact placement of.certain families in the different suborders. The system of Brues and
Melander (1932) is adopted with some slight variations.
The suborder RHYNCHOPHTHIRINI has been erected by Ferris (Parasitology 23:
112-127,1931) to include the elephant louse, H{lJmatomyzu5 elephantis Piaget, which has generally
been associated with the sucking lice in the order ANOPLURA.