CLASS I. INSECTA: ORDER 1. COLEOPTERA. 
541 
the perfect insect than in the cases above referred to, although the pupa is active and continues 
to feed until the time of its arrival at the imago state. We may therefore call this a sub-com- 
2)lete metamorphosis. Lastly, a few insects, which possess no wings in the perfect state, undergo 
no change, except in size, from the time of their emerging from the egg to that of their reach- 
ing maturity. 
The immense number of insects, and their diversified forms, habits, and endowments, have 
rendered their classification a matter of great labor, and often of extreme embarrassment. In 
the account we propose to give, we sliall chiefly aim at simplicity of arrangement, and endeavor 
to select from the endless mass of species only those which may be considered as possessing some 
peculiar point of interest. Referring the reader to Vol. L, page 28, for the details of our classi- 
fication, wc need only state here that we shall notice the Class of Insects under the following 
thirteen orders: Coleo2)tcra, Strepsii^tera, Jlymeno2:)tera, Lepidoptera, Biptera, A2Jhani2)tera, Neii- 
ropiera^ Orihoptera^ Physopoda^ jRhynchota, Thysanura^ Mallophaga^ and Anoplura. 
THE SUGAR BEETLE — PASSALUS, 
ORDER 1. COLEOPTERA. 
C'oleo2Jtera is derived from the Greek koleos, a sheath, and ptera, wings, and includes the Beetles 
or Sheatli-winged Insects, of which nearly forty thousand species are known. Their leading 
characteristic, alluded to in the name of the order, consists in the leathery or horny texture of 
the anterior wings, called elytra by naturalists, which serve as sheaths for the posterior wings in 
repose, and generally meet in a straight line down the back. The posterior wings are membra- 
neous, and much larger than the anterior pair ; they are the sole organs of flight, and are folded 
both longitudinally and transversely, when not in use. The moiTth is formed for biting; the 
mandibles are almost always strong, somewhat triangular, horny organs, which, in the predaceous 
beetles, are hooked and sharp at the points, and often arined with acute teeth on the inner 
margin; while in many herbivorous species, the inside of the basal portion is transversely ridged, 
to fit the jaws for the comminution of vegetable substances. In some beetles, which feed upon 
fluid matters, the mandibles are dilated into membraneous hairy plates. In some cases, as in 
the common stag-beetle, the mandibles are of great size, and some allied species have them still 
larger. The maxillse exhibit diflferences in form corresponding with those of the mandibles. 
The other organs attached to the head are the antennse and the eyes. Tlie antennse are gen- 
erally composed of from nine to eleven joints, and are inserted upon the forehead between the 
eyes, sometimes close to those organs, sometimes more in the middle of the head. Compound 
eyes exist in nearly all beetles ; they are placed on the sides of the head, and are generally of a 
