The Carabidae, or ground-beetles, comprising 13,000 species, form FIG.
The identification of the elytra of beetles with the fore-wings of other insects has indeed been questioned (1880) by F.
As regards growth after hatching, all beetles undergo a "complete" metamorphosis, the wing-rudiments developing beneath the cuticle throughout the larval stages, and a resting pupal stage intervening between the last larval instal1 and the imago.
Two very small families of aquatic beetles seem to stand at the base of the series, the Amphizoidae, whose larvae are broad and well armoured with FIG.
It is possibly for the purpose of feeding on parasitic mites that book-scorpions lodge themselves beneath the wing-cases of large tropical beetles; and the same explanation, in default of a better, may be extended to their well-known and oft-recorded habit of seizing hold of the legs of horse-flies or other two-winged insects.