The basal ventral plates of the abdominal segments are somewhat shorter in the middle than at the sides, the fourth one being often invisible in the middle, while the fifth is very large. Sub-fam. 2. Camptosomes; with six divisions, Megascelides, Megalopides, Clythrides, Cryptocephalides, Chlamydes, Sphaerocarides.
In the other two groups there is no great disparity between the fourth and fifth ventral plates.
Prothorax not greatly narrower at the base than the elytra, and usually with distinct edges at the outsides. Sub-fam. 3. Cyclica; with four divisions, Lamprosomides, Eumolpides, Chrysomelides, Galerucides.
Front of the head bent downwards or inflexed, so that the mouth is on the lower aspect. Antennae inserted close together on the most anterior part of the head, so that they are more forward than the mouth. Sub-fam. 4. Cryptostomes; with two divisions Hispides, Cassidides.
In the other three divisions the mouth is placed as usual, but the insertion of the antennae varies a good deal.
The larvae of about 100 species of the family are known; they are arranged in accordance with their habits, by Chapuis,[[145]] in six groups, viz.:
1. Elongate larvae, living under water, and there undergoing their metamorphosis. (Donaciides.)
2. Larvae mining in leaves, and undergoing their metamorphosis in the leaf. (Hispides and some Halticides.)
3. Short convex larvae, frequently with leathery and pigmented integuments, living exposed on plants. (Most of the Cyclica.)
4. Larvae of short form; covering the body with excrementitious matter. (Some Criocerides.)