FAM. 41. LATRIDIIDAE.—_Tarsi three-jointed; anterior coxal cavities round, not prolonged externally; abdomen with five visible and mobile ventral segments._ Very small Insects, species of which are numerous in most parts of the world, the individuals being sometimes very abundant. The larvae (Fig. 120, A) are said by Perris to have the mandibles replaced by fleshy appendages. The pupa of _Latridius_ is remarkable, on account of the numerous long hairs with heads instead of points; the larva of _Corticaria_ is very like that of _Latridius_, but some of the hairs are replaced by obconical projections. The sub-family Monotomides is by many treated as a distinct family; they have the elytra truncate behind, exposing the pygidium, and the coxae are very small and very deeply embedded. Most of the Latridiidae are believed to live on fungoid matters; species of _Monotoma_ live in ants' nests, but probably have no relations with the ants. A few species of Latridiides proper also maintain a similar life; _Coluocera formicaria_ is said to be fond of the stores laid up by _Aphaenogaster structor_ in its nests. About 700 species are now known; scarcely any of the individuals are more than one-tenth of an inch long. We have about 40 species in Britain. The North American genus _Stephostethus_ has the prosternum constructed behind the coxae, somewhat in the same manner as it is in the Rhynchophorous series of Coleoptera. [Illustration: Fig. 120—_Latridius minutus._ Britain. A, Larva (after Perris); B, perfect Insect.] FAM. 42. ADIMERIDAE.—_Tarsi appearing only two-jointed, a broad basal joint and an elongate claw-bearing joint, but between the two there are two very small joints._ This family consists only of the American genus _Adimerus_; nothing is known of {241}the life-history of these small Insects. They are of some interest, as this structure of the foot is not found in any other beetles. [Illustration: Fig. 121—_Adimerus setosus._ Adimeridae. A, the Insect; B, one foot more enlarged. Mexico. From _Biol. Centr. Amer. Col._ ii. pt. i.] [Illustration: Fig. 122—_Tiresias serra._ Larva. New Forest.]