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Palæarctic has 2, but none peculiar; the Ethiopian 13, with 11 peculiar; the Oriental 8, with 3 peculiar; the Australian 9, with 2 peculiar; and the Neotropical 15, with 10 peculiar. The connection between South America and Australia is shown by the latter country possessing 9 species of the characteristic South American genus Tetracha, as well as one of Megacephala. The small number of peculiar genera in the Oriental and. Australian regions is partly owing to the circumstance that two otherwise peculiar Oriental genera have spread eastward to the Moluccas and New Guinea, a fact to be easily explained by the great facilities such creatures have for passing narrow straits, and by the almost identical physical conditions in the Malayan portion of the two regions. The insects of Indo-Malaya were better adapted to live in the Austro-Malay Islands than those of Australia itself, and the latter group of islands have thus acquired an Oriental aspect in their entomology, though not without indications of the presence of an aboriginal insect-fauna of a strictly Australian type. The relation of the Australian and Neotropical regions is exhibited by this family in an unusually distinct manner. Tetracha, a genus which ranges from Mexico to La Plata, has 9 species in Australia; while Megacephala has 2 American and 1 Australian species. Another curious, and more obscure relation, is that between the faunas of Tropical America and Tropical Africa. This is also illustrated by the genus Megacephala, which has 4 African species as well as 2 South American; and we have also the genus Peridexia, which has 2 species in South America and 2 in Madagascar.
Several of the sub-regions are also well characterised by peculiar genera; as Amblychila and Omus confined to California and the Rocky Mountains; Manticora, Ophryodera, Platychile, and Dromica, characteristic of South Africa; Megalomma and Pogonostoma peculiar to the Mascarene Islands; and Caledonica to the islands east of New Guinea. The extensive and elegant genus Collyris is highly characteristic of the Oriental region, over the whole of which it extends, only just passing the limits into Celebes and Timor.
The Cicindelidæ, therefore, fully conform to those divisions of VOL. II.-32
the earth which have been found best to represent the facts of distribution in the higher animals.
CARABIDÆ. (620 Genera, 8500 Species.) The enormous extent of this family, necessitates a somewhat general treatment. It has been very extensively collected, while its classification has been most carefully worked out, and a detailed exposition of its geographical distribution by a competent entomologist would be of the greatest interest. A careful study of Gemminger and Harold's Catalogue, however, enables me to sketch out the main features of its distribution, and to detail many of its peculiarities with considerable accuracy.
The Carabidæ are remarkable among insects, and perhaps among all terrestrial animals, as being a wonderfully numerous, varied, conspicuous, and beautiful group, which is pre-eminently characteristic of the Palæarctic region. So strikingly and unmistakably is this the case, that it must be held completely to justify the keeping that region distinct from those to which it has at various times been proposed to join it. Although the Carabidæ are thoroughly well represented by hosts of peculiar genera and abundant species in every part of the world without exception, yet the Palæarctic region alone contains fully onethird, or perhaps nearer two-fifths, of the whole. It may also be said, that the group is a temperate as compared with a tropical one; so that probably half the species are to be found in the temperate and cold regions of the globe, leaving about an equal number in the much more extensive tropical and warm regions. But, among the cold regions, the Palæarctic is pre-eminent. North America is also rich, but it contains, by far, fewer genera and fewer species.
The magnificent genus Carabus, with its allies Procerus and Procrustes, containing about 300 species, all of large size, is almost wholly confined to the Palæarctic region, only 10 species iuhabiting North America, and 11 Temperate South America, with one on the African mountain of Kilimandjaro. Twelve large genera, containing together more than 2000 species, are truly cosmopolitan, inhabiting both temperate and tropical countries all over the globe; but many of these are more abundant in the Palæarctic region than elsewhere. Such are Scarites, Calosoma, Brachinus, Cymindis, Lebia, Chlonius, Platynus, Harpalus, Bembecidium, Pæcilus, and Argutor. Of tropical cosmopolites, or genera found in all the tropical regions, but not in the temperate zones, there seem to be only four, -Catascopus, Coptodera, Colopodes, and Caasuonia Pheropsophus is confined to the tropics of the Old World ; while Drimostoma, though widely scattered, is characteristic of the Southern Hemisphere.
The Palæarctic region has about 50 genera of Carabide which are strictly confined to it, the most important being,-Leistus (30 sp.), Procerus (5 sp.), Procrustes, (17 sp.), Zabrus (60 sp.), Pristonychus (42 sp.), and Ophonus (60 sp.); but it possesses a large number in common with the Nearctic region. The more remarkable of these are,—Carabus, Nebria, Amara, Cyrtonotus, Bradycellus, Anopthalmus, Celia, Cychrus, Patrobus, Elaphrus, Notiophilus, Bradytus, Callisthenus, Blethisa, and several others. Many too, though not strictly confined to the North Temperate regions, are very abundant there, with a few species isolated in remote countries, or widely scattered, often in an eccentric manner. Among these may be mentioned, Trechus (120 sp.), all North Temperate but 8, which are scattered in Java, New Caledonia, and South America ; Dyschirus (127 sp.), North Temperate, with 3 or 4 species in Australia, China, and La Plata ; Omaseus, (88 sp.), Steropus (90 sp.), Platysoma (114 sp.), and Pterostichus (138 sp.), are mostly North Temperate, but each has a few species in the South Temperate zone, New Zealand, Australia, Chili, and the Cape of Good Hope. Dromius (54 sp.), is about two-thirds Palæarctic, the rest of the species being scattered over the world, in Chili, North and South America, South Africa, Burmah, Ceylon, and New Zealand. The North Temperate genera Calathus and Olisthopus, have each one species in New Zealand; Percus has most of its species in South Europe, but 3 in Australia; Abax is confined to the north temperate zone, but with one species in Madagascar; while Læemosthenes is said to have a species identically the same in South Europe and Chili. Some of these apparent anomalies may be due to wrong
determination of the genera, but there can be little doubt that most of them represent important facts in distribution.
The Nearctic region is comparatively poor in Carabidæ. Its more important peculiar genera are,—Dicælus (22 sp.), Pasimachus (17 sp.), Eurytrichus (9 sp.), Sphæroderus (7 sp.), Pinacodera (6 sp.), and others of smaller extent, about 30 in all. It also possesses representatives of a considerable number of Palæarctic genera, as already indicated ; and a few of South American genera, of which Helluomorpha and Galerita are the most important.
The Neotropical region is very rich in peculiar forms of Carabidæ, as in almost all other great groups. It possesses more than 100 peculiar genera, but about 30 of these are confined to the South Temperate sub-region. The more important peculiar genera of Tropical America are,–Agra (144 sp.), Ardistomus (44 sp.), Schizogenius (25 sp.), Pelecium, (24 sp.), Calophena (22 sp.), Ctenodo.ctyla (7 sp.). Among the Chilian and South Temperate peculiar forms are,–Antarctia (29 sp.), Scelodontis (10 sp.), Tropidopterus (4 sp.). Among the Neotropical genera with outlying species are,—Pachyteles (50 sp.), one of which is West African; Selenophorus (70 sp.), with 4 African, 4 Oriental, and 1 from New Caledonia ; Ega (11 sp.), with one in the East Indies, and one in New Caledonia ; Galerita, with 36 American species, 8 African, and 3 Indian; Callida and Tetragonoderus, mostly American, but with a few African, Oriental, and Australian species; and Pseudomorpha, common to America and Oceania.
The Australian region is almost equally rich, possessing about 95 peculiar genera of Carabidæ, no less than 20 of which are confined to New Zealand. The most important are, Carenum, Promecoderus, Scaraphites, Notonomus, Ænigma, Sphallomorpha, Silphomorpha, and Adelotopus. The gigantic Catadromus has 4 Australian species and 1 in Java; Homalosoma has 31 species in Australia and New Zealand, and 1 in Madagascar. Celebes and New Guinea have each peculiar genera, and one is common to Australia and the Cape of Good Hope.
The Oriental region possesses 80 peculiar genera, 10 of which are confined to Ceylon. The more important are,—Pericallus, Planetes, and Mormolyce. Distrigus is also characteristic of this region, with'one species in Madagascar; while it has Orthogonius, Hexagonia, Macrochilus, and Thyreopterus in common with the Ethiopian region, and is rich in the fine tropical genus, Catascopus.
The Ethiopian region has 75 peculiar genera, 8 of which are confined to Madagascar. The more important are,—Polyhirma, Graphipterus, and Piezia. Anthia is chiefly African, with a few species in India; Abacetus is wholly African, except a species in Java, and another in South Europe; and Hypolithus is typically African, but with 7 species in South America and 1 in Java.
The facts of distribution presented by this important family, looked at broadly, do not support any other division of the earth into primary regions than that deduced from a study of the higher animals. The amount of speciality in each of these regions is so great, that no two of them can be properly united ; and in this respect the Carabidæ accord wonderfully with the Vertebrates. In the details of distribution there occur many singular anomalies ; but these are not to be wondered at, if we take into consideration the immense antiquity of Coleopterous insects—which existed under specialised forms so far back as the Carboniferous epoch,—the ease with which they may be dispersed as compared with larger animals, and the facilities afforded by their small size, habits of concealment, and often nocturnal habits, for adaptation to the most varied conditions, and for surviving great changes of surface and of the surrounding organic forms. The wonder rather is, not that there are so many, but so few cases of exceptional and anomalous distribution ; and the fact that these creatures, so widely different from Vertebrates in organisation and mode of life, are yet on the whole subject to the same limitations of range as were found to occur among the higher animals, affords a satisfactory proof that the principles on which our six primary regions are founded, are sound; and that they are well adapted to exhibit the most interesting facts of geographical distribution, among all classes of animals.
Much stress has been laid on the fact of a few species of such typical European genera as Carabus, Dromius, and others, being