LIBRA R^Y OF THE UNIVERSITY Of ILLINOIS

590.6 LI

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THE

JOURNAL

OF

THE LINNEAN SOCIETY.

ZOOLOGY.

VOL. XI.

LONDON:

SOLD AT THE SOCIETY'S APARTMENTS, BURLINGTON HOUSE;

AND BY

LONGMANS, GREEN, READER, AND DYER,

AND

WILLIAMS AND NORGATE.

1873.

PRINTED BY TAYLOR AND FRANCIS, KED LION COURT, FLEET STREET.

LX

LIST OF PAPERS.

Pag

Allis, Thomas, F.L.S.

On the Skeleton of the Apteryx 523

Baird, W., M.D., F.R.S., &c.

Description of some new Species of Annelida and Gephyrea in the collection of the British Museum 94

Burmeister, Dr. Hermann, F.M.L.S.

Observations on a Light-giving Coleopterous Larva 416

Cambridge, Rev. 0. P., M.A.

On some new Species of European Spiders* (Plates XIV. & XV.) 530

COLLINGWOOD, CUTHBERT, M.A., F.L.S., &C

On a new Form of Cephalopodous Ova. (Plate I.) 90

Day, Surgeon-Major Francis, F.L.S. , &c.

On some new Fishes of India 524

Garner, Robert, F.L.S.

On the Formation of British Pearls and their possible Improve- ment 426

Gulick, Rev. John T.

On Diversity of Evolution under one set of External Conditions. 496

Kirby, W. F., Assistant in the Museum of the Royal Dublin Society. On the Geographical Distribution of the Diurnal Lepidoptera as compared with that of the Birds 431

Lubbock, Sir John, Bart, F.R.S., F.L.S. On the Origin of Insects 422

M'Lachlan, Robert, F.L.S., Sec. Ent. Soc.

On new Forms, &c, of Extra-European Trichopterous Insects.

(Plates II., III., & IV.) 98

An Attempt towards the Systematic Classification of the Family Ascalaphidse 219

Muller, Albert, F.L.S.

Note on a Chinese Artichoke-Gall (mentioned and figured in Dr. Hance's paper " On Silkworm-Oaks ") allied to the Eu- ropean Artichoke-Gall of Aphilothrix gemmae ; Linn 428

iv

Page

Murie, James, M.D., F.L.S., &c.

Notes on the White-beaked Bottlenose, Lagenorhynchus albi-

rostris, Gray. (Plate V.) . 141

Murray, Andrew, F.L.S.

On the Geographical Relations of the Chief Coleopterous Faunae. .1

Ormerod, Miss Eleanor A.

Observations on the Cutaneous Exudation of the Triton cristatus, or Great Water-Newt 493

Pascoe, Francis P., F.L.S., late Pres. Ent. Soc.

Contributions towards a Knowledge of the Curculionidse.

Part II. (Plates VI., VII., VIII., & IX.) 154

Contributions towards a Knowledge of the Curculionidse. Part III. (Plates X., XI., XII., XIII.) 440

Potts, Thomas H., Esq., F.L.S.

Notes on Keropia crassi?'ostris, Gml. (" Piopio ") 505

Saunders, Edward, F.L.S.

Descriptions of Buprestidae collected in Japan by George Lewis, Esq 509

Smith, F. Esq.

A Catalogue of the Aculeate Hymenoptera and Ichneumonidae of India and the Eastern Archipelago, with Introductory Re- marks by A. R. Wallace. (Communicated by W. W. Saunders, Esq.) 285

Trimen, Roland, F.L.S., F.Z.S., M.E.S.

Note on a Paper by Andrew Murray, F.L.S., " On the Geo- graphical Relations of the Chief Coleopterous Faunae " .... 276

Index 549

THE JOURNAL

or

THE LINNEAN SOCIETY.

On the Geographical Relations of the Chief Coleopterous Faunae. By Andrew Murray.

[Read December 17, 1868.] *

Judging simply from their structure, habits, and economy, there are reasons why Beetles ought to excel every other class of organ- ized beings as exponents of the past geography of the globe. I say so after having turned over in my mind and contrasted every class of animals and plants with each other with the view of de- termining for myself which would be most likely, through the study of its geographical distribution, to throw light upon the past history of the earth. I can think of none so likely to do so as insects, and of insects as Beetles.

Over all marine animals they have the insuperable advantage of inhabiting the enclosed instead of the enclosing spaces, of living on dry land and not being able to go beyond it. Over plants, with which their distribution in many respects accords, they have the advantage of being more difficult of dissemination, for neither their eggs nor themselves are endowed with the dormant vitality of seeds, nor with that endurance of exposure to different condi-

* This paper was read on December 17, 1868, but by permission of the Council I have brought it down to the state of our knowledge at the date of publication. —A. M.

LINN. PROC. ZOOLOGY, YOL. XI. 1

2

MR. A. MURRAY ON THE GEOGRAPHICAL RELATIONS OE

tions which may, and occasionally does, enable seeds to be carried in the stomachs of birds or floated across wide oceans to distant lands *. They have also the advantage over the larger and more highly organized animals in that they can survive and find food where the latter could not. Their food is so various that nothing but a total extinction of all other life could wipe them off from the face of a country a partial submergence of land for even a short period might destroy every mammal upon it, but so long as a tree-top is above the flood or an uncovered rock remains on which they can take refuge, the life of the Beetle class is safe when the waters abate. A succession of cold seasons in which no plant can bloom might destroy those kinds of animals for which, like the bee, flowers and honey are necessaries of life, some bee- tles might indeed then go ; but there are plenty that feed on leaves or stems to preserve the Beetle type in the frozen land. Their numbers, too, multiply the chances of escape in the case of dis- aster, and their powers of flight enable them to take advantage of such as occur. Further, the powers of flight, although sufficient for a moderate distance, are not like those of birds, so great as to carry them to new lands at great distances and so to risk the dis- turbance of faunas which such powers, if possessed by such mul- titudes, might possibly produce. In many respects, too, they are as much adstrieti glebes as plants themselves, for a vast host are limited each to one particular plant for food. As in plants, in- deed, there are some kinds of Beetles more open than others to the suspicion of having been introduced from one isolated land to another, as, for example, the timber-borers or Longicorns. But there are others, as the hunting or carnivorous species, the apte- rous species, the blind insects, and others of less specialized struc- ture, whose presence in discontiguous countries seems to bid defi- ance to any explanation other than that of former continuity of soil. In Madeira, for instance, where the number of admittedly introduced species is very great, there is not one introduction be- longing to the hunting families ; and if this is the case there, not-

* It is a digression, but it is worth making one, to point out that if plants can be disseminated in the way supposed, and Beetles, or certain families of Beetles, can not, the attempt to explain the distribution of the former as due either solely or mainly to these means must be abandoned in every case where their distribution corresponds with that of the latter. The common elfeet must have been produced by a common cause. And it so happens that this correspondence exists in all the more important and puzzling facts of distribution.

THE CHIEF COLEOPTEROUS FAUNJE.

3

withstanding the accessibility of Madeira to the introducing agencies of man (to which most of the other introductions are referable), it becomes still more difficult to conceive of the dis- semination of that kind of beetles by agencies independent of man.

But besides the advantages which the structure, habits, and economy of beetles give for the interpretation of their geographi- cal distribution, there is another important speciality inherent in them which I shall amply illustrate in the course of this paper, and which renders them peculiarly available for the study of its problems, viz. a long-enduring persistency of form by which the same type has been preserved through diverse modifications during many geological epochs. This peculiarity is shared by all other insects, as well as in different degrees by all beings of inferior organization ; and the consequence is that in trying to make out the past history of a country through its fauna and flora, we must take each class of beings by itself and study its relations separately, or we shall run the risk of confounding events belong- ing to different dates. To do otherwise would be like attempting to compile a history of England by combining the political history of one age with the ecclesiastical of another and the scientific of a third. The mammalian fauna took its present form long after the insects had received theirs, and these earlier-dated forms should therefore be able to tell of events long antecedent to what the mammals could speak of. The relations of each must there- fore be studied independently, and it is only after all shall have been separately deciphered that the conclusions respectively drawn from each can be brought together and some common general result arrived at. In the mean time, by endeavouring to ascertain the relative date of appearance of insects of various types in dif- ferent countries, we may be able to assign the order of precedence of a succession of events whose occurrence we can scarcely doubt, but whose order of date we could not otherwise guess at.

My purpose in the present paper is to submit some infer- ences of this nature from a general view of the geographical dis- tribution of the Coleoptera, indicating a somewhat different ar- rangement of land and water in ancient times from that which is usually supposed, and to strengthen these inferences by references to what seem to me corresponding facts in other branches of na- tural history.

The first point to which 1 shall direct attention is the very in -

1*

4

MR. A. MURRAY ON THE GEO GRAPHICAL RELATIONS OF

teresting problem of the occurrence of similar forms in the tem- perate and cold regions of both hemispheres. Hitherto the hypotheses by which this has been attempted to be explained have, I believe, either been : 1st, by accidental introduction ; 2nd, by the supposition that the glacial epoch had so modified the climate of the globe as to allow an extension or interchange of faunas lying on different sides of the equator ; 3rd, by the suppo- sition that one general fauna had formerly extended over the whole world, and that the similarities which we find in antipodal countries are relics of this general fauna ; and 4th, that a former geographical connexion with identity of fauna and flora must have subsisted between the two regions. There is another hypothesis to the effect that the similar species are representative species, meaning by representative something different from derivative and independent of affinity. This latter proposition, I frankly confess, is beyond my conception. I cannot conceive of any other kind of representation in species than that arising from derivation. The other hypotheses are entitled to more consideration, and I shall briefly state my opinion upon each.

As to similarity being due to the introduction of species by accidental dispersal, it is to be noted that this cause must always be in its very nature exceptional and isolated, and cannot be expected to make its impress on a whole fauna.

The Atlantic islands, for example, which were, and perhaps still are, very generally cited as an instance of colonization by acci- dental introduction, have been shown by Mr. Wollaston to have all one coleopterous subfauna, and that one peculiar to themselves. The general basis is European, but overlying that is something else, a number of species of special type found in all and found no- where else. Now if these islands, as is maintained by some, have been peopled by chance visitors from Europe, how have they all got in addition this special type ? and why should there be, as in Trophonius Cave, " vestigia nulla retrorsum " ? "Why have none of these special forms ever wandered to Europe ? Why should things only come from Europe and nothing ever go back in re- turn ? There is no law against reciprocity here, and yet it is rigorously excluded. Moreover the explanation, if true, should apply to every part of the globe, and illustrations of its existence should be in greatest force in the lands which are nearest to each other and which have most intercourse with each other. And this is notoriously not the case. Australia, although so much

THE CniEF COLEOPTEROUS FA.UNJE.

5

nearer India than Cliili, has more affinity with the latter than the former. The Cape-Verde Islands, although so near Cape Verde, have their affinity not with Africa, but with Europe and the other Atlantic Islands. Even in the introductions by man it does not apply. Hear what DeCandolle says of plants. " I am surprised that the commerce of the United States, with Brazil, Chili, New Zealand, the Sandwich Islands, and China, a commerce which has been carried on with great activity for upwards of thirty years, has not yet brought about the naturalization of species from these regions. Up to the present time there is no appearance of it. The Bubieva multifield, which has begun to appear at New York, and of which the naturalization is not yet consolidated by the proof of time, is the only plant perhaps which has come in this manner. In future some will arrive, without doubt." [Why so ? Surely not from what has happened in the past ?] " They may compen- sate to some extent perhaps the probable diminution of those which will come from Europe"*.

Facts are accumulating upon us to show that diffusion of plants and animals by accidental circumstances beyond physical barriers, such as seas or impassable mountains or deserts, bears no import- ant part in the establishment of any definite fauna or flora. They bear a part, although a small one, in the introduction of occasional new elements into a fauna or flora ; but these remain like lumps of stone lying on a soil with which they can neither become in- corporated nor harmonize, usually readily distinguishable and re- ferable to the mountains or strata more or less distant from which they have come. Actual continuity of soil and non-interruption by barriers is, I believe, the only cause by which any fauna with a definite character (and no true fauna is without one) has been produced, and subsequent isolation, at least so far as regards phy- sical conditions, that by which it has been preserved. The coral islands of the Pacific are a case in point. They have been sup- plied both with a fauna and flora entirely from without and by chance dispersal ; and they furnish an admirable example of the kind and amount of inhabitants that is to be got by such intro- ductions, even under the most favourable circumstances of tran- quil seas, warm climate, and favouring currents ; and allowance to such an extent I am always ready to make in examining the ele- ments of any fauna or flora. The details of such a fauna and flora will be given further on when I come to discuss the fauna of * DeCandolle, Geogr. Botanique raisonnee, p. 755 (1855).

6 ME. A. MURRAY ON THE GEOGRAPHICAL RELATIONS OE

the Pacific islands ; in the meantime I may briefly characterize it as meagre to the last degree, most unequal in its proportions, and all traceable to the shores of the nearest lands from which the currents set.

The supposition that the existence of the similarity in ques- tion is due to the facilities for migration to or from the northern or southern hemispheres afforded by the low temperature of the glacial epoch is open to various answers. But it is unnecessary to discuss them at all ; for I shall presently show that the re- semblances to which I have to refer were already in existence before the glacial epoch commenced, consequently could not have been caused by it.

The hypothesis that similar forms occurring at distant places are the remains of a general fauna (or, at least, of a more general fauna than now exists), which had in former times ex- tended over the whole or the greater part of the world, is more attractive or more formidable.

I used to think that in that hypothesis I had a satisfactory explanation of all such anomalies as I speak of. Like Shak- speare's barber's chair, it fitted all comers. If the similarity was widely spread, it was due to universal prevalence in former times. If found only in one or two isolated spots, then there were solitary relics of a once universally distributed type ! But I confess that my faith in my specific has latterly been a good deal shaken. It costs me nothing to say so, for consistency is a vice to which I have never been addicted. I believe it still to be probably the true explanation of those cases (as in Ferns, for example) where the same type is very widely and gene- rally distributed; but I have abandoned it for most isolated instances, and for all specially localized faunas. In the first place, although I do not dispute that in the earlier stages of the history of our planet there was a greater homogeneity of type than there is at present, it seems pretty well established now, that there have been geographical regions with faunas and floras differing from each other, not indeed to the same degree as now, but to some extent, from the very earliest times of which we have any fossil record ; and in the next place, although it is not impos- sible that a universally distributed form may have died out every- where but in one or more specified spot or spots, the doctrine of chances prevents us accepting the hypothesis whenever such relics cease to be solitary. Species No. 1 may be a relic left at

THE CHIEF COLKOL'TEItOUS IfAUNiE.

7

spots A and B, and nowhere else ; but the moment we find another supposed relic, species No. 2, also left in A and B, and nowhere else, doubt assails us, and increases in an inverse ratio with the occurrence of every additional relic.

The fourth supposition is, I think, the true one, namely, continuity of soil at some former period ; and upon that as a basis I rest the propositions I am about to submit. Upon it, I think, I can explain satisfactorily many of the remarkable in- stances of peculiar geographical distribution which have hitherto defied the ingenuity of naturalists to solve, and notably that which I have first set before me, viz. the resemblance which species from the temperate regions of the northern hemisphere bear to those from similar latitudes in the southern hemisphere. With the help of the above postulate I can trace the links all the way from the one to the other plainly in insects, plants, and land-shells, and more imperfectly in the higher animals ; but also in them, if allowance be made for the greater variability in form in the higher animals under change of condition of life, and their distribution be examined in relation to the geographical epochs in which the different forms respectively came into being and most prevailed. The absence of particular mammals in a particular land cannot vitiate my theory, if the distribution of animals in it had been completed before the mammals appeared.

For the better understanding of my argument I shall first state the results at which I have arrived.

The position I am about to maintain then is, that, subject to modifications to be afterwards mentioned, all the Coleoptera in the world are referable to one or other of three great stirpes. These three no doubt originally sprung from one stirps, and ac- quired their distinguishing features by long-continued isolation from each other, combined with changes in their conditions of life. But now we have three, and only three, great strains, sometimes intermingling with each other, sometimes underlying or overlying each other, and sometimes developed into new forms, but always distinguishable and traceable to one or other of the three sources.

These are 1, the Indo- African stirps ; 2, the Brazilian stirps ; and 3, what, for want of a better name, I shall call the micro- typal stirps, in allusion to the general run of the species com- posing it being of a smaller size, or, more strictly speaking, not containing such large or conspicuous insects as the others. It

8 MR. A. MURRAY ON THE GEOGRAPHICAL RELATIONS OE

is not altogether a satisfactory name, because the stirps does con- tain some large species, and it is not peculiar to it to abound in small ones. But, taken as a whole, its ingredients are smaller and more modest in appearance than those of the others. The fauna and flora of our own land may be taken as its type and standard.

A like tripartite basis may be traced in every class of beings. It may happen, indeed, that one or other of them, as the Bra- zilian stirps in mammals (Edentata &c, for example), may have almost died out ; in others some former stirps, extinct in all the rest, may have survived in some isolated part of the world (as plants in Australia) ; but, subject to such exceptional modifica- tions, the leading features of my proposition will be found gene- rally applicable to all. It does not come within the scope of my present paper to show more than its application to Coleoptera ; but I do not mean to deprive myself of the aid to be derived from the occurrence of a similar arrangement in other classes of organized beings, whenever I find that my position needs strength- ening. In many points our materials for working out the sub- ject are so meagre that they require every collateral aid, and it is obvious that the more widely I can show the arrangement to apply, the more will my conclusions, as to their occurrence in the Coleoptera, be strengthened.

The Indo- African stirps, as its name implies, inhabits Africa south of the Sahara, and India and China south of the Hima- layas, also the Malayan district, the Indian archipelago, and the New Guinea group. This range is less modified by the general introduction of foreign elements than that of the next stirps.

The Brazilian stirps inhabits South and Central America east of the Andes, and north of the River Plate, and furnishes, moreover, a large share in the constitution of North America, but has also received in return a very perceptible tinge from the microtypal stirps.

In the microtypal stirps I include the fauna of Europe, Asia north of the Himalayas, Eastern North America, so far as not modified by the Brazilian element ; and, what has less of this strain, the whole of North-west America, California, part of the Mexican fauna, Peru, Chili, the Argentine Republic south of Tucuman, Patagonia, Tierra del Euego, Polynesia, New Zealand, and Australia.

When I first broached this view to one of my friends, I was

THE CHIEF COLEOPTEROUS FAUN7E.

9

met by the exclamation, " "What ! Australia and Europe the same ! Nonsense : Australia, of all places, is the least like Europe ; when you go there you pass into a wholly new country : everything is reversed there ; the very leaves grow upside down ; it is like visiting some great city of the dead ! "

I grant it in some things, but not in all. Before I have done, I trust to prove that, in conformity with the principle I started with (that we must not judge of the fauna of one class by the fauna of another), it is not so in Beetles. It must be remem- bered that the present flora of Australia once flourished in Europe. Professor Unger may have occasionally allowed his imagination too free a rein, and the determinations of many of the fossil species by him and Professor Heer on which he based his conclusions in his 'New Holland in Europe' may be in- sufficient or erroneous, but the fact will not be disputed that the Eocene Mora of Europe has many points of correlation with the present flora of Australia. The resemblance no longer exists in the living floras of the two countries ; in Australia alone has the old flora survived.

As regards insects, on the other hand, we know, from the re- searches of Heer and other naturalists, that the Beetle-fauna of Europe in the Miocene time was of the same type as the present Beetle-fauna of Europe and Asia. There are, unfortunately, no similar materials applicable to the Eocene epoch, nor has any one utilized the lesser materials that exist as Heer has done for the Miocene epoch ; but from the fact that the insects derived from the still older beds of the Stonefield slate belong to the same stirps (I say so on my own authority and from personal examination), and that the whole of the Miocene materials yet made public, although drawn from several places and beds of dif- ferent age, all belong to one fauna, it seems probable that the Entomological Fauna of Europe in the Eocene age was the same as in the Miocene. It is an assumption, but not wholly without warrant ; and starting from it, my hypotheses is that, like the Eocene Elora in Australia, it has survived in its Eocene form down to the present day ; only it has done so more perfectly in England than Australia, while the flora has only done so at^all in the latter. In short, I should hold that if the researches of Sir Charles Lyell should end in carrying back the antiquity of man to the Eocene time, and if the ghost of an Eocene naturalist were to be allowed to revisit the glimpses of the moon, he would

10 MR. A. MURRAY ON THE GEOGRAPHICAL RELATIONS OF

find in Australia the type of both the plants and beetles very much as he left them. In Europe he would find only the beetles. Indeed I am strongly disposed to claim even a greater antiquity for our present Coleopterous fauna. Some may remember that when insect remains were first found in the coal-formations, the surprise was general among naturalists at finding them so small in size and so little different from those of the present day. They expected that they should have been as much beyond the existing type in size and splendour as the Megalicthys ex- ceeds a Herring. Nature, according to the notions of those days, was in her youth in the Carboniferous epoch, and they ex- pected something of the extravagance of youth in her proceedings. It now seems more probable that the Coleopterous fauna there was the same in type then as now, and that it has continued so in the region I speak of for all the intervening period, in accord- ance with the rule already referred to, that the lower we descend in the scale of organization, the more persistent is the general character of the forms of which life is composed.

It is not a reply to say that the Eocene flora, which has changed in Europe, being lower in the scale of life than the fauna, should have been equally persistent. It is not lower in the scale of life than insects. They are not in the same scale at all. They are on two distinct and separate ladders ; and the Eocene plants, which have changed, were high up on their ladder (the very mammals of vegetable life), while the Eocene Coleopterous fauna was low down on its. It is to be borne in mind, too, that we have every reason to believe that the changes in condition of life since the Eocene epoch have been much greater and more frequent in Europe than in Australia ; and if the plants are ac- cepted as being more likely to change than the insects under altered conditions in life, it is in Europe rather than in Australia that a change in them was to be expected.

Of course, in what I have been saying, and shall further say on this subject, I speak of the Coleopterous fauna of Australia as a whole. In one sense it cannot be disputed that it is dif- ferent from that of Europe. The species are not the same, and there are a multitude of peculiar forms ; but the type, especially of what I regard as the more important test-groups, such as the hunting unintroduceable species, is the same. The peculiar forms can almost always be traced back to enlargement or deve- lopment of some micro typal form. Putting aside such exceptions,

THE CHIEF COLEOPTEROUS FAUNJE.

II

the general facies is the same, and a large proportion of the genera are the same, and it will be still greater when we get rid of the feeling that the genera must necessarily be different, because they come from such a distant country. Some of the species are scarcely distiaguishable from our own, and even the relative proportions of numbers of species and genera in different groups are the same.

My conviction is, that there has been certainly one, possibly two, great continental routes of communication between the northern and southern hemispheres, both now lying buried in the ocean, the one at the bottom of the Atlantic, the other in the depths of the Pacific ; and I hope, from an examination of the traces left on the ruined piers which mark the course of these ancient viaducts, to show the course that they took and the inhabitants that used them.

If any one, following in the steps of Sir Charles Lyell, ob- jects to such a wholesale erection of continents on the ground of their magnitude, I have only to remind them of the vast extent of land which has appeared above water since the Tertiary epoch. Some drying up of the ocean during that period no doubt has taken place, but nothing sufficient to account for the immense tracts of country which have become dry land ; and it is not a matter open to argument or discussion, but a mathema- tical necessity, that if land, previously below the water, comes above it, a corresponding quantity of land which was previously above it must then go below it.

Let us now turn to the three great stirpes, and pass each of them in review, trace their course, and determine their limits. I shall begin with the microtypal stirps (with which we are most familiar). It is the most extensive of the whole, being distributed over the whole world, with the exception of the In- dian, African, and Brazilian regions ; and even they, from va- rious exceptional causes, have a greater or less tinge of it in their faunas. It contains some minor faunas, and these, again, a number of subfaunas. The Europeo-Asiatic region is one of these minor faunas, and of it the Atlantic islands, the Me- diterranean, and the Mongolian are subfaunas. Taken as one fauna, the Europeo-Asiatic extends from the Azores east to Japan, the whole of that vast space being inhabited entirely by the same type and, for the most part, by the same species, a few only dropping off here and there, and being replaced by

12 ME. A. MURRAY ON THE GEOGRAPHICAL RELATIONS OF

others of the same general character. As to the Atlantic islands, the task is easy to decipher their relations ; Mr. Wollaston has done it ready to my hand in his various admirable researches on their Coleoptera. It would be idle to vaunt the merits of his works to Fellows of the Linnean Society. Mr. Wollaston is one of our number, and we are entitled to regard his honours as gems in our own chaplet, if not laurels of our own growth. In interpreting the faunas of these islands, I have only to recapitu- late the results of his researches ; on almost every point I arrive at the same conclusions that he has done. He has removed all possibility of doubt as to the general identity of the faunas of the northern groups with that of Europe, and notably with the Me- diterranean section of that fauna, or as to their individual identity with each other as members of one and the same subfauna. In the Madeiran group (see ' Insecta Maderensia ' and ' Catalogue of Madeiran Coleoptera') he showed that out of 580 species, 314 are species already known on the Continent of Europe ; true, he considers (in which he goes further than I would) that so many as 120 of these had been imported by man, or otherwise found their way to the islands ; but, even after deducting these, he leaves 194 known European species aboriginally present, as against 266 endemic species. These endemic species, again, are all akin to the European forms, fit easily into their places among them, and all possess the facies of that fauna. I have already alluded to the want of reciprocity between Madeira and Europe in regard to any specialities they possess, and shall merely illus- trate that remark by noting the fact that, although Mr. Wol- laston credits Europe with a recent remittance of nearly the half of the European species, he acknowledges that no repayment in kind has ever been made by Madeira, not a single example of any of its peculiar species having ever found its way to Europe, ex- cept in an entomologist's box ; and this, be it remembered, although the means of introduction have been at least as open on the return as on the outward voyage *.

In the Canary Islands (see ' Catalogue of Canarian Coleoptera')

* I know it may be replied to this that an unusual proportion of the Madeiran endemic species are apterous ; but this, even although it were a good answer, would only account for the deficiency of a proportion equivalent to the relative number of apterous, as against winged species ; but it is not a good answer even as regards them ; for no one supposes that the introduction of species from the continent to Madeira has been by actual flight. It is floating wood and birds that are usually referred to as the vehicle or mode of transmission.

THE CHIEF COLEOPTEHOUS FA.UNJ3.

L3

Mr. Wollaston next found that out of a total of 930 species, 224 are identical with Madeiran species, and, notably, that the same peculiar types which gave to Madeira the character of a subfauna, are also present there in force. The Cape-Verde Islands tell the same tale. Previous to the appearance of Mr. Wollaston's 1 Coleoptera Hesperidum,' the usual belief among entomologists was, that the fauna of the Cape- Verde Islands partook more of that of the coast of Africa, nearest which they lie, than that of any other country. Mr. Wollaston has shown that this is a mistake. In his introductory remarks he says, " Our recent explorations in the Cape Verdes have shown their Coleopterous population to be so far more than I had anticipated on the Canarian and Madeiran type, that I am anything but certain that it would not be more natural to regard the whole of these Atlantic islands as characterized by a single fauna un- mistakably the same, even whilst necessarily differing as to many of its exact details (and through the fact of mere distance) in the more widely separated groups." From my own materials I rather inclined to the more general notion, and I therefore care- fully tested Mr. Wollaston's conclusions by his data, and the result fully corroborated his view. Out of 275 Cape- Verde species, 91 were common to the Canaries, and 81 to the Ma- deiran group. The African element proved slight, as Wollaston said, and such as might fairly enough be referred to chance in- troductions from the opposite coast of Africa. The European element continues, as before, the staple, and a new phase of the peculiar endemic subfauna of Madeira is also a characteristic element of its fauna.

In support of the above statements, I shall merely specify one or two of the most striking of the types which are present in all the Atlantic-island groups under the same or similar forms. In Madeira the Heteromera are characterized by the presence of the endemic genera Hadrus and Hegeter, Hadrus having three spe- cies, Hegeter only one. In the Canaries, Hadrus has disappeared, but Hegeter has nineteen species, and in the Cape Verdes He- geter is reduced to one, but a new form, Oxycara, has taken its place with ten species. In Madeira, the Curculionidae are dis- tinguished by a profusion of Cossonidae containing new genera and new species in a marked degree. The same prevails in all the islands ; so with Acalles, a small genus with few species in Europe, but with an especial redundancy in all the islands. Atlantus or

14 MR. A. MURRAY ON THE GEO GRAPHICAL RELATIONS OF

Laparocerus is another special new development confined to them, but present in most of them in greater or lesser numbers ; thus in Madeira there are thirteen species, in the Canaries thirty- five species, none in the Cape Verdes, where, however, Dinas, a new Brachyderidous insect, similar to it in appearance, comes either to take its place or that of Brachyderes, which is also found in some of the Atlantic groups. In the Clavicorns, the remarkable genus Tarphius, a consideration of whose relations would require space which cannot be given here, characterizes the Canaries and Madeira, as Attains does in the Malacodermata.

As to the Azores, Mr. Crotch has completed Wollaston's work for him there. As a matter of sentiment, one would have liked to have seen the whole finished by Mr. Wollaston himself, as he had done so much and so well ; but the naturalist is rather un- grateful in this respect, and cares little how he gets his know- ledge, provided he does get it. Mr. Crotch's contribution there- fore (Proc. Zool. Soc. 1867) is a welcome, as it is a trustworthy and careful, record of the Coleoptera of the Azores. His mate- rials are, indeed, far less complete than Wollaston's in the other islands ; but although imperfect as regards proportions, they suf- ficiently reveal the character of the fauna. Mr. Crotch records 213 species, of which 160 are European ; and among those not European, he describes a Tarphius, a Laparocerus, an Attalus, an Acalles, and a new member of the Cossonidse all sufficient indications of the Azores being a member of the same system as the other Atlantic islands. How the European character of this general fauna is to be accounted for, except on the supposition of a former connexion of them all with Europe, and how the presence of these special forms of the same subfauna in all the islands, and nowhere else, is to be accounted for except on the supposition that, after they were disunited from Europe, they were still united among themselves, it is for those who advocate the theory of dispersal by chance introductions to say.

The Azores seem to occupy nearly the western extremity of this ancient land ; not far beyond them a deep valley, the deepest part of the Atlantic, intervenes between them and the coast of America. Up this the G-ulf-stream scours, as it probably has done from early days far back in geological time ; and if there is any place in the world to which we might reasonably expect a few waifs and strays to be brought by currents, it would be the Azores ; and yet there are only three in this position, all Brazilian

THE CHIEF COLEOPTEROUS FAUNAE.

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and all insects which probably pass their larval state in timber ; they are an Elaterid (a species of JSolus, JE. tnelliculus), which is found all along the coast of South America from Rio to Demerara, Monocrepidius posticus, another Elater which is otherwise confined to the La- Plata district in South America, and Tamioles scalaris, a Longicorn. In the other Atlantic islands there is only one such introduction, a North- American Longicorn {Glytus erythrocepha- lus\ which has been found on the Salvages. The supposed in- troductions to the Azores from the European side of the Atlantic are, according to Mr. Crotch, much more numerous. He divides the 170 European species of the Azores into " two groups (70 possibly indigenous and 101 almost certainly introduced by colo- nists) and the mode of introduction assigned by him is (I know not on what grounds or with what prima facie probability) their importation in earth at the roots of garden-plants. Certainly in this case the operations of the chance-introduction theory (three species coming with the current against 101 against it) would seem to call for some apology or explanation ; but those who, like myself, reject that theory as capable of doing any thing more than furnishing accidental exceptions, will only see in the 101 supposed introductions (probably, but not necessarily, under deduction of a few cosmopolitan species) 101 natural denizens belonging to the microtypal stirps, and present in their natural capacity of legiti- mate descendants of the aboriginal heirs of the soil.

The only remaining vestiges which may be supposed to have formed part of this ancient Atlantis are Ascension Island, St. Paul's, St. Helena, and Tristan d'Acunha.

Of these, St. Paul's is, I believe, beyond its limits, and belongs to another fauna and another stirps, its fauna, so far as I know, being Brazilian ; but more information is still wanted regarding it.

Ascension Island is a barren rock of recent formation, said to be almost without any fauna but what has been introduced by man within a hundred years or so ; but it has never been tho- roughly examined by any competent naturalist. What we do know of it has been picked up during brief flying visits by natu- ralists who, like Mr. Darwin, touched at its port, and did what they could in a limited time. The only animals recorded, so far as I know, are one Slug (Limax ascensionis), and, if we go by that, we must put it down as microtypal, and two Sea-shells (IA- torina milaris and Nerita ascensionis) , found by Mr. Cumming on its shores.

16 ME. A. MURRAY ON THE GEOGRAPHICAL RELATIONS OP

St. Helena, that great puzzle of naturalists, is a crucial test to my hypothesis of a communication between the northern and southern hemispheres by an Atlantic continent ; if that link snaps, the whole chain will fall to the ground. It will, of course, not touch the evidence for a communication between the northern and southern hemispheres by the Pacific ; but a microtypal St.- Helena fauna is vital to an Atlantic communication. I say that its fauna is certainly microtypal, and if so, almost necessarily a branch of the Atlantic type of that stirps ; there is nothing else microtypal within reach for it to be attached to. Some three years ago Dr. Hooker gave an admirable lecture on oceanic islands *, in which he discussed the origin of the flora of St. He- lena, and on the whole seemed inclined to refer it to Africa. More in the spirit of " audi alteram partem " than from any settled conviction of my own, I wrote a reply t, in which I gave some reasons for thinking that it might more probably have been originally connected with and peopled from Europe, although also possibly connected at some period with Africa. More ma- ture consideration and subsequent researches have confirmed my opinion; and the following examination of the character of its plants and animals will show the grounds on which I rest it.

In mammals, of course, nothing is to be expected. The only allusions to them that I can find is the statement J that in cutting away the lava at Ladder Hill, many feet below the surface, small bones have been found, apparently about the size of those of a rat, and more particularly a small rib-bone entirely covered with an incrustation