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North and South America; Smerinthus (29 sp.), all regions except Australia. Our Death's Head Moth (Acherontia atropos) ranges to Sierra Leone and the Philippine Islands.
General Remarks on the Distribution of the Diurnal Lepidoptera
and Sphingidea. The Diurnal Lepidoptera or Butterflies, comprehend 431 genera and 7,740 species, arranged in 16 families, according to Mr. Kirby's Catalogue published in 1871. The Sphingidea consist of 135 genera and 1,255 species, arranged in 7 families, according to the British Museum Catalogue dated 1864; and as this includes all Mr. Bates' collections in America and my own in the East, it is probable that no very large additions have since been made.
The distribution of the families and genera of Butterflies corresponds generally with that of Birds—and more especially with that of the Passerine birds—in showing a primary division of the earth into Eastern and Western, rather than into Northern and Southern lands. The Neotropical region is by far the richest and most peculiar. It possesses 15 families of butterflies, whereas the other regions have only from 8;' in the Palæarctic, to 12 in the Ethiopian and Oriental regions; and as none of the Old World regions possess any peculiar families, the New World has a very clear superiority. In genera the preponderance is still greater, since the Neotropical region possesses about 200 altogether peculiar to it, out of a total of 431 genera, many of which are cosmopolitan. Comparing, now, the Eastern regions with the Western, we have two peculiar families in the former to 4 in the latter; while the Southern regions (Australian and Neotropical) possess not a single peculiar family in common.
In the Sphingidea the same general features recur in a less marked degree, the Neotropical being the richest region; but here we have one family (Castniidæ) which appears to be confined to the two southern regions,—the Australian and Neotropical.
The distribution of the genera affords us some facts of special · interest, which must be briefly noticed. There are several
genera typically characteristic of the North Temperate regions which have a few species widely scattered on mountains, or in the temperate parts of the Southern Hemisphere. Chili possesses representatives of four of these genera— Argynnis, Lycona, Colias, and Deilephila ; and this has been thought by some naturalists to be of such importance as to outweigh the purely Neotropical character of a large portion of the Chilian fauna, and to render it advisable to join it on, as an outlying portion of a great North Temperate zoological region. But when we remember that Argynnis occurs also in Java, and Lycona in New Zealand, while Colias ranges to Southern Africa, Malabar, and the Sandwich Islands, we can hardly admit the argument to be a sound one. For a fuller discussion of this question see Vol. II., pp. 43—47. The remarkable fact of the existence of the otherwise purely Neotropical genus, Urania, in Madagascar is even more striking, supported as it is by the Antillean, Solenedon, belonging to a family of Mammalia otherwise confined to Madagascar, and by one or two Coleopterous genera, to be noticed farther on as common to the two countries. Our view as to the true explanation of this and analogous phenomena will be found at Vol. I., p. 284.
The division of the Castniidæ (a family almost confined to the Tropics), between the Neotropical and Australian regions, is also a very curious and important phenomenon, because it seems to point to a more remote connection between the two countries than that indicated by the resemblance between the productions of South Temperate America with those of Australia and New Zealand; but we have already shown that the facts may be explained in another way. (See Vol. I., pp. 398 and 404).
The division of the Malay Archipelago between the Oriental and Australian regions is clearly marked in the Lepidoptera, and it is very curious that it should be so, for in this, if in any group of animals, we should expect an almost complete fusion to have been effected. Lepidoptera fly readily across wide tracts of sea, and there is absolutely no climatal difference to interfere with their free migration from island to island. Yet we find no less than 10 genera abundant in the Indo-Malayan
sub-region which never cross the narrow seas to the east of them; 6 others which only pass to Celebes; and 2 more which have extended from Java along the closely connected line of islands eastwards to Timor. On the other side, we find 5 strictly Austro-Malayan genera, and 2 others which have a single representative in Java. The following is a list of these genera :
INDO-MALAYAN GENERA :-Amathusia, Thaumantis, Tanccia, Eurytela, Ilerda, Zemeros, Taxila, Aphneus, Prioneris, Dercas, Clerome, Adolias, Apatura, Limenitis, Iolaus, Leptocircus, (the last six reach Celebes); Discophora, Thestias; (the last two reach Timor.).
AUSTRO-MALAYAN GENERA : Hamadryas, Hypocista, Mynes, Dicallaneura, Elodina, Hyades, Prothoë (the last two reach Java).
The most characteristic groups, which range over 'the whole Archipelago and give it a homogeneous character, are the various genera of Danaidæ, the genus Elymnias, and Amblypodia with a few other Lycænidæ. These are all abundant and conspicuous groups, but they are nevertheless exceptions to the general rule of limitation to one or other of the regions. The cause of this phenomenon is probably to be found in the limitation of the larvæ of many Lepidoptera to definite species, genera, and families of plants; and we shall perhaps find, when the subject is carefully, investigated, that the groups which range over the whole Archipelago feed on genera of plants which have an equally wide range, while those which are limited to one region or the other, have foodplants belonging to genera which are similarly limited. It is known that the vegetation of the two regions differs largely in a botanical sense, although its general aspect is almost identical ; and this may be the reason why the proportion of wide-ranging genera is greater among such insects as feed upon dead wood, than among those which derive their support from the juices of the living foliage. This subject will be again discussed under the various families of Coleoptera, and it will be well to bear in mind the striking facts of generic limitation which have been here brought forward.
FAMILY 16.-HESPERIDÆ. (52 Genera (?) 1,200 Species.)
PALÆARCTIC ETHIOPIAN ORIENTAL
184.108.40.206 220.127.116.11 18.104.22.168 22.214.171.124 126.96.36.199 188.8.131.52
· The Hesperidæ, or Skippers, are an immense group of mostly small obscurely coloured butterflies, universally distributed, and of which hosts of species still remain to be discovered and described. As the grouping of these into genera is not yet satisfactorily accomplished, only the more extensive and best known groups will be here noticed. Pamphila and Hesperia are universally distributed; Nisoniades seems to be only absent from the Australian region. The Neotropical region is preeminently rich in Hesperidæ, 33 genera being found there, of which 20 are peculiar to it; the Australian region has 12 genera, only 1 (Euschemon)' being peculiar; the Oriental has 18, with 3 peculiar; the Ethiopian, 13, with 3 peculiar; the Palæarctic 6, with 1 (Erynnis) almost peculiar, a species occurring in Mexico; the Nearctic 9, with none peculiar, 4 being found also in the Neotropical region, 2 in the Palæarctic, and the rest being of wide distribution. Many new genera have, however, been recently described in the United States, but it is impossible yet to determine how many, if any, of these are peculiar. More than 100 species of the family are included in Mr. Edwards' “Synopsis of North American Butterflies,”—a very large number considering that Europe possesses only about 30. I pakubor.
Sub-order-LEPIDOPTERA HETEROCERA, or MOTHS.
· The Lepidoptera Heterocera, or Moths, are of such immense extent, and are, besides, so imperfectly known compared with the Butterflies, that it would serve no purpose to go into the details of their distribution ; especially as most of the families and a considerable number of the genera are cosmopolitan. We propose therefore to notice only the Sphingina, which, being generally of large size and finely marked or coloured, and many of them day-fliers, have been extensively collected; and whose numbers are more manageable than the succeeding groups.
FAMILY 17.—ZYGÆNIDÆ (46 Genera, about 530 Species).
The Zygænidæ are universally distributed, but many of the genera are restricted in their range. Zygaena (85 sp.) is mainly Palæarctic, but 2 species are South African, and 1 North American; Procris (22 sp.) has a scattered distribution, from the Palæarctic region to South America, South Africa, and North India ; Heterogynis (3 sp.) and Dysauxis (3 sp.) are European ; Pollanisus (3 sp.) is Australian; Glaucopis (120 sp.) is mainly Neotropical, with a few Oriental; Syntomis (94 sp.) is found in all the Old-World regions; and Euchromia (150 sp.) is found in all warm countries, though especially abundant in South America.
FAMILY 18.—CASTNIIDÆ (7 Genera, 63. Species).
The Castniidæ have an interesting distribution, being mainly Neotropical, with four genera in Australia and New Guinea. Castnia, Coronis, and Gazera, with 51 species, are Neotropical ; Synemon, Euschemon, Damias, and Cocytia, with 12 species, are Australian, the latter being found only in the Papuan Islands.