Sharp (1899), who divides the order into six great series of families: Lamellicornia (including the chafers and stag-beetles and their allies with five-segmented feet and plate-like terminal segments to the feelers); Adephaga (carnivorous, terrestrial and aquatic beetles, all with five foot-segments); Polymorpha (including a heterogeneous assembly of families that cannot be fitted into any of the other groups); Heteromera (beetles with the fore and intermediate feet five-segmented, and the hind-feet four-segmented); Phytophaga (including the leaf-beetles, and longhorns, distinguished by the apparently four-segmented feet), and Rhynchophora (the weevils and their allies, with head prolonged into a snout, and feet with four segments).
Lameere (1900) has suggested three sub-orders, the Cantharidif ormia (including the Phytophaga, the Heteromera, the Rhynchophora and most of the Polymorpha of Sharp's classification), the Staphyliniformia (including the rove-beetles, carrion-beetles and a few allied' amilies of Sharp's Polymorpha), and the Carabidiformia (Adephaga).
Horn placed the Rhynchophora (weevils) in a group distinct from all other beetles, on account of their supposed primitive nature.
- The Rhynchophora are a group of beetles easily recognized by the elongation of the head into a beak or snout, which carries the feelers at its sides and the jaws at its tip. The third tarsal segment is broad and bi-lobed, and the fourth is so small that the feet seem to be only four-segmented.
The ventraPscleriteof the head-skeleton (gula), well developed in most families of beetles, is absent among the Rhynchophora, while the palps of the maxillae are much reduced.
The Bruchidae are often called "weevils," but they have no close affinity with the Rhynchophora, being nearly allied to the Chryso - melidae or leaf beetles.