Of or pertaining to the tarsus, ankle, or instep of the foot: correlated with carpal: as, tarsal bones; tarsal articulations.Of or pertaining to the tarsometatarsus of a bird, commonly called the tarsus, between the heel and the bases of the toes: as, the tarsal envelop; tarsal scutella.Of or pertaining to the last segment of an insect's leg: as, tarsal joints; tarsal claws.Of or pertaining to the tarsi of the eyelids: as, tarsal cartilages; the tarsal muscle.Heteromera, having the four anterior tarsi five-jointed and the two posterior four-jointed;Tetramera, having four joints to all the tarsi;Trimera, having three joints to all the tarsi.To these Latreille added Dimera, having two joints to all the tarsi, andMonomera, having but a single tarsal joint in each foot. Some of these divisions are now known to have rested on imperfect observations, and all are subject to exceptions among closely allied species; hence the tarsal system has been generally abandoned or modified, though in many respects it approached a natural classification, and, admitting the exceptions, the divisions can still be used with advantage. Its convenience is such that attempts have also been made to retain it, in its general features, with substitution of other names intended to correct the early imperfect observations, as Cryptopentamera, Pseudotetramera, Subpentamera, etc.; and the adjectives derived from all these terms, as pentamerous, heteromerous, etc., are regularly used in describing beetles and their tarsi.n. A tarsal bone (or cartilage); one of the elements of the tarsus of the foot, intervening between the tibia and the metatarsus; especially, a tarsale. See tarsus.