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(Nymphalidæ) a fine genus which has 4 Antillean species and 2 in Central America; Lucinia (Nymphalidæ) 2 species, confined to Jamaica and Hayti ; and Kricogonia belonging to the Pieridæ, which has 2 West Indian species, while 1 inhabits Mexico and Florida Genera which show a special relation to Central America are Euptoieta, Eumæus, and Nathalis. Almost all the other genera are South American, the total number recorded in each family as occurring in the West Indian islands, being, 3 of Danaidæ; 1 of Heliconiidæ; 2 of Satyridæ ; 18 of Nymphalidæ; 1 of Erycinidæ ; 4 of Lycænidæ ; 6 of Pieridæ; 1 of Papilionidæ, and 10 of Hesperidæ. The genus Papilio is represented by about 20 species, 2 of which are North American, 4 South American, while the rest form little characteristic groups allied to those of Central America. The most marked feature seems to be the scarcity of Satyride and the almost total absence of Erycinidæ, with a great deficiency in characteristic Neotropical forms of Danaidæ and Nymphalidæ.

Coleoptera.—Cicindelidæ and Carabidæ are very poorly represented, by a few species of wide-spread groups, and hardly any peculiar genera. No Lucanidæ are recorded. Of Cetoniidæ, Gymnetis only appears to be represented. Buprestidæ seem to be more numerous ; 15 genera being recorded, but almost all of wide distribution. One only is peculiar— Tetragonoschoma, found in Hayti; Halecia is the only exclusively South American genus; Chalcophora is widely scattered over the tropical regions but is absent from South America, yet it occurs in the Nearctic region and extends to Jamaica and Guadeloupe. We now come to the Longicorns, the only group of Coleoptera which seems to be well represented, or which has been carefully collected. No less than 40 genera are known from the West Indian islands, and 15 of these are peculiar. Prionidæ are proportionately very numerous, there being 10 genera, 2 of which are widely distributed in both South and North America, 1 is North American, and 1 South American, while the following are peculiar,— Stenodontes (Hayti and Cuba); Dendroblaptus (Cuba); Monodesmus (Cuba and Jamaica); Prosternodes (Cuba); Solenoptera ard Elateropsis, the two largest genera, found in most of the islands. Of Cerambycidæ there are 16 genera, 2 of which range all over America, 4 are Neotropical, 1 South American only, while the following are confined to the islands - Merostenus, Pentomacrus, and Eburiola (Jamaica); Bromżades (Cuba) ; Trichrous, Heterops, and Pæciloderma (Antilles). One genus, Smodicum, is widely spread, having a species in Carolina, 1 in South America, 1 in Hayti, and 1 in West Africa. Of Lamiidæ there are 14 genera, 8 of which are Neotropical, 1 common to Central America and Mexico, 1 to the United States and Cuba, while 2, Proecha and Phidola, are confined to Cuba. Several of the genera are curiously distributed ;-Spalacopsis is South American, with 4 species in Cuba and Tropical Africa ; Lagocheirus is Neotropical, with a species in Australia ; while Leptostílus is characteristic of the Antilles and North America, with a few species in South America, and one in New Zealand. These cases of erratic distribution, so opposed to the general series of phenomena among which they occur, must be held to be sufficiently explained by the great antiquity of these groups and their former wide distribution. They may be supposed to be the remnants of types, now dying out, which were once, like Callichroma, Clytus, and many others, almost universally distributed

All the peculiar Antillean genera of Cerambycidæ and Lamüdæ are allied to Neotropical forms. The peculiar Prionidæ, however, are mostly allied to Mexican and North American groups, and one, Monodesmus, belongs to a group all the other genera of which inhabit the East Indies and South Africa.

Land-shells.—This subject has already been generally treated under the Region, of which, in this class of animals, the Antilles form so important a part. We must therefore now confine ourselves mainly to the internal distribution of the genera, and to a few remarks on the general bearing of the facts.

The excessive and altogether unexampled productiveness of the West Indian islands in land-shells, may be traced to two main sets of causes. The first and least known, consist of the peculiar influences and conditions which render islands always more productive than continents. Whatever these conditions

are, they will be more effective where the islands have been long separated from the mainland, as is here undoubtedly the case. It seems most probable that the great development of landshells in islands, is due to the absence or deficiency of the vertebrata, which on continents supply a variety of species adapted to prey upon these molluscs. This view is supported by the fact, that in such islands as have been united to a continent at no very distant epoch, and still maintain a continental variety of vertebrata, no such special development of land-shells has taken place. If we compare the Philippine islands with the Sunda group, we find the development of vertebrata and land-molluscs in inverse ratio to each other. The same thing occurs if we compare New Zealand and Tasmania; and we have a still more striking example in the Antillean group itself, continental Trinidad having only 20 genera and 38 species, while the highly insular Jamaica has about 30 genera and more than 500 species.

The other causes favourable to the increase and development of land-shells are of a physical nature. A great extent of limestone-rock is one; and in the larger West Indian islands we have a considerable proportion of the surface consisting of this rock. But perhaps equally or more important, is the character of the land surface, and the texture of the exposed rock itself. A much broken surface, with numerous deep ravines, cutting up the whole country into isolated valleys and ridges, seems' very favourable to the specialization of forms in this very sedentary class of animals. Equally favourable is a honeycombed and highly-fissured rock-surface, affording everywhere cracks and crannies for concealment. Now, taking Jamaica as an example of the archipelago, we find all these conditions in a wonderful degree. Over a large part of this island, a yard of level ground can hardly be found; but ridges, precipices, ravines, and rockbound valleys, succeed each other over the whole country. At least five-sixths of the entire surface is limestone, and under the influence of tropical rains this rock is worn, fissured, and honeycombed, so as to afford ample shelter and concealment for landshells.

It is probable that the three chief islands, Cuba, Jamaica, and Hayti, are nearly equally rich in land-shells; but the last is very much less known, and therefore, perhaps, appears to be much poorer. Cuba has rather more species than Jamaica ; but while the former has only 1 peculiar genus (Diplopoma), the latter has 3 (Geomelania, Chittya, and Jamaicea), as well as two others only represented in the other islarids by single species. From Hayti, only about one-third as many species are known as froin the two former islands. It has no peculiar genera, but it has some forms in common with Cuba and others with Jamaica, which show that those islands have more connection with it, than with each other; just as we found to be the case in birds. Portorico and the Virgin islands have still fewer species than Hayti; and, as many of the genera common to the other three islands are wanting, there is, no doubt, here a real deficiency. In the islands farther south (Barbuda to Martinique) more Antillean genera disappear or become very rare, while some continental forms take their place. The islands from St. Lucia to Trinidad have a still more continental character; the genus Bulimus, so largely developed on the continent, only reaching St. Lucia. The Bahamas contain about 80 species of land-shells, of which 25 are Antillean, the rest peculiar; all the genera being Antillean. The affinity is chiefly with Hayti and Cuba, but closest with the latter island.

In the West Indian islands as a whole, there are 11 peculiar genera ; 9 operculate (Geomelania, Chittya, Jamaicea, Licina, Choanopoma, Ctenopoma, Diplopoma, Stoastoma, Lucidella); and 2 inoperculate (Sagda and Stenopus), besides Cyclostomus, which belongs to the Old World and is not found on the American continent. Mr. Bland considers, that many of the Antillean land-shells exhibit decided African and Asiatic, rather than South American affinities. A species of the Asiatic genus Diplommatina has been found in Trinidad, and an Indian species of Ennea occurs in Grenada and St. Thomas; a clear indication that land-shells are liable to be accidentally imported, and to become established in the less productive islands.

Although these islands are so wonderfully rich even now, there is good reason to believe that many species have become extinct since the European occupation of them. When small islands are much cultivated, many of these molluscs which can only live under the shade of forests, are soon extirpated. In St. Croix many species have become extinct at a comparatively recent period, from the burning of forests; and as we know that in all the islands many of the species are excessively local, being often confined to single valleys or ridges, we may be sure that wherever the native forests have disappeared before the hand of man, numbers of land-shells have disappeared with them. As some of the smaller islands have been almost denuded of their wood, and in the larger ones extensive tracts have been cleared for sugar cultivation, a very considerable number of species have almost certainly been exterminated.

General Conclusions as to the Past History of the West Indian Islands. The preceding sketch of the peculiarities of the animal life of these islands, enables us to state, that it represents the remains of an ancient fauna of decided Neotropical type, having on the whole most resemblance to that which now inhabits the Mexican sub-region. The number of peculiar genera in all classes of animals is so great in proportion to those in common with the adjacent mainland, as to lead us to conclude that, subsequent to the original separation from the Mexican area, a very large tract of land existed, calculated to support a rich and varied fauna, and, by the interaction of competing types, give rise to peculiar and specially modified organisms. We have already shown that the outline of the present islands and the depths of the surrounding seas, give indications of the position and extent of this ancient land ; which not improbably occupied the space enclosed by uniting Western Cuba with Yucatan, and Jamaica with the Mosquito Coast. This land must have. stretched eastward to include Anguilla, and probably north ward to include the whole of the Bahamas. At one time it perhaps extended southward so as to unite Hayti with northern Venezuela, while Panama and Costa Rica were sunk beneath the Pacific. At this time the Lesser Antilles had no existence.

The only large island of whose geology we have any detailed

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