CLASS I. INSECTA: ORDER 1. COLEOPTERA. 



541 



the perfect insect than in the cases above referred to, altliough tlie 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- 

 plete 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 

 tlie account we propose to give, we shall 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. I., page 28, for the details of our classi- 

 fication, we need only state here that we shall notice the Class of Lisects under the following 

 thirteen orders: Coleoptera, Strepslptcra, Hymcnoptera, Lepidoptera, Diptera, Aphaniptera^ Neu- 

 roplcra, Orthoptera, Phi/sopoda, Jthynchota, Thysanura, Mallophaga^ and Ano2)lura. 



--=-- ^'^'T?^- 



THE S0GAU BEETLE PASSALUS. 



ORDER 1. COLEOPTERA. 



ColeopAtra is derived from the Greek koleos, a sheath, and j^cra, wings, and includes the Beetles 

 or Sheath-winr/ed 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 mouth 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 armed 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 

 1 11 aid matters, the mandibles are dilated into membraneous hairy plates. In some cases, as in 

 [ llio coiiniiou stag-beetle, the mandibles arc of great size, and some allied species have them still 

 j larger. The maxilla? exhibit differences in form corresponding with those of the mandibles. 



The otlier organs attached to the head are the antennfc and the eyes. Tlie antennfe arc 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 



