Longicornia.--The Neotropical Longicorn Coleoptera are overwhelming in their numbers and variety, their singularity and their beauty. In the recent Catalogue of Gemminger and Harold, it is credited with 516 genera, 489 of which are peculiar to it; while it has only 5 genera in common (exclusively) with the Nearctic, and 4 (in the same way) with the Australian region. Only the more important genera can be here referred to, under the three great families into which these insects are divided.
The Prionidæ are excessively numerous, being grouped in 64 genera, more than double the number possessed by any other region; and 61 of these are peculiar. The three, common to other regions, are, _Parandra_ and _Mallodon_, which are widely distributed; and _Ergates_, found also in California and Europe. The most remarkable genera are, the magnificently-coloured _Psalidognathus_ and _Pyrodes_; the large and strangely marked { 18}_Macrodontia_; and _Titanus_, the largest insect of the entire family.
Of the Cerambycidæ there are 233 genera, exceeding by one-half, the number in any other region; and 225 of these are peculiar. Only 2 are common to the Neotropical and Nearctic regions exclusively, and 3 to the Neotropical and Australian. The most extensive genera are the elegant _Ibidion_ (80 sp.); the richly-coloured _Chrysoprasis_ (47 sp.); the prettily-marked _Trachyderes_ (53 sp.); with _Odontocera_ (25 sp.); _Criodon_ (22 sp.); and a host of others of less extent, but often of surpassing interest and beauty. The noteworthy genera of wide range are, _Oeme_ and _Cyrtomerus_, which have each a species in West Africa, and _Hammatocerus_, which has one in Australia.
The Lamiidæ have 219 genera, and this is the only tropical region in which they do not exceed the Cerambycidæ. This number is almost exactly the same as that of the Oriental genera, but here there are more peculiar groups, 203 against 160 in the other region. The most extensive genera are _Hemilophus_ (80 sp.), _Colobothea_ (70 sp.), _Acanthoderes_ (56 sp.), _Oncoderes_ (48 sp.), _Lepturgus_ (40 sp.), _Hypsioma_ (32 sp.), and _Tæniotes_ (20 sp.). _Macropus longimanus_, commonly called the harlequin beetle, is one of the largest and most singularly-marked insects in the whole family. _Leptostylus_ has a single species in New Zealand; _Acanthoderes_ has one species in Europe, W. Africa, and Australia, respectively; _Spalacopsis_ has a species in W. Africa; _Pachypeza_ is common to S. America and the Philippines; _Mesosa_ is Oriental and Palæarctic, but has one species on the Amazon; _Apomecyna_ ranges through the tropics of the Eastern Hemisphere, but has two species in S. America; _Acanthocinus_ has one species in Tasmania, and the rest in South America, North America, and Europe; _Phæa_ is wholly Neotropical, except two species in the Philippine Islands.