climatic changes, and are limited in their distribution by the isothermal lines or by the extent of rainfall. Thus, a desert may prove impassable for one species, while another may be equally unable to surmount the barrier presented by a low swampy tract, a high mountain range or a great plateau. The valley of a large river, with its gradual slope and protected nooks, forms a natural highway for the passage of migrating or spreading species.

Within the Great Basin of North America, certain problems of insect distribution are presented in almost perfect purity. In these desolate areas ale spots rarely trodden by the foot of man, still supporting the life that has been theirs since the time when the valleys were filled with lakes that have left their tide-marks and old beach lines hundreds of feet up the sides of ine Wasatch and the Sierra Nevada; inland seas of fresh water, gradually dwindling away as the result of widespread climatic changes, and now represented only by the few meagre salt and bitter lakes that mark the bottom of the ancient bed. Even these remnants are in danger of disappearance through the loss of their tributaries, diverted for irrigation, so that if we are to study the insects peculiar to their borders the work should not be delayed.

The Great Basin lies between the Wasatch and the Sierra Nevada. It includes the western part of Utah, nearly all of Nevada, a great part of eastern and southern California, extending a short distance down the Peninsula. It also takes in a portion of southern Oregon, and small sections of Idaho and Wyoming. Though termed the Basin, it is chiefly high plateau, fringed by still higher mountains, whose outer slopes drain into the Colorado and the Columbia, excepting along the western edge where the surplus rainfall is gathered up by the Sacremento and other rivers that discharge more directly into the Pacific Ocean. The moisture which falls within the limits of the Great Basin, however, can escape only in one way, namely by evaporation. None of the streams rising there ever break through the rim nor reach the ocean. The rivers either waste away on the vast deserts or empty their floods into shallow lakes that act as evaporating pans, precipitating the solid matters and returning the rest to the air again. As a consequence of this continual concentrating of the fluids, the waters of the lakes are nearly all strongly alkaline or saline, often so bitter as to be useless for drink. The shores are incrusted with salt and soda, sometimes the deposits are several inches in thickness. These beaches, in spite of their forbidding appearance, support a life peculiar to themselves-they are inhabited by an assemblage of insects fitted for just such conditions, and existing nowhere else.

The lakes are separated by immense tracts of desert-black volcanic rock, old hard-baked mud flats or wide valleys of sand, according to the forces that have been at work in the making of the land. Much of the valley country is in the neighborhood of five thousand feet above the sea, but it falls off to the southwest where it occasionally sinks several hundred feet below the level of the ocean. In the northern part, the climate is moderate, in the southwest it is extremely hot, but certain features are common to the district as a whole the air is very dry and the rainfall scanty, so there is a constant, though not regular, dwindling of the water bodies. The plant life is essentially that of the desert except on the higher mountain ranges where the trees occasionally reach a profusion of growth which we may call forest.

It is, however, with the insects that we are mostly concerned, and of the insects we are best acquainted with the Coleoptera. Several types are quite characteristic of the Basin, hardly occurring outside of it, or at most barely passing the borders. In this category, may be mentioned Cicindela echo, a fine tiger beetle; Cicindela tenuicincta: Tanarthrus salicola and its allies, small species frequenting the borders of alkaline lakes and ponds; three hairy

Eleodes, circus bugs as they are called in the West; and a considerable number of the genus Bembidium, ground beetles that pick up a living on the shores of streams and pools, not dwelling at any considerable distance from moisture. Many others might be named, but I have endeavored to call attention only to a few of the more striking instances.

In studying the shore-inhabiting species just mentioned, the question has arisen, whence do they owe their origin? Are they immigrants from the surrounding lands, and if so, do they come from the north or south, the east or west? Do they have. near allies on the shores of lakes lying outside of the Great Basin, or are they isolated types that may be supposed to have arisen n the ground they now occupy? My own belief, founded on several years' work with material collected on my trips to nearly every part of the Great Basin and the surrounding districts, is that they are true endemics-that they have undoubtedly arisen, as species, in their present locations or the immediate vicinity thereof. Occasionally a small colony may be established in the outlying districts adjacent to the Basin, but such cases are rare. study of the distribution of some of the principal types, will, in my mind, cast a good deal of light on the question as to whether or not these beetles are recent acquisitions to the Basin fauna. It is unnecessary to enter into details here, as I have gone over the matter with more minuteness in a paper now in press.

A

Taking as an example, one of the tiger beetles, Cicindela echo Casey, we find it distributed as follows,-on the mud beaches of Great Salt Lake, Utah Lake, Sevier Lake and Little Salt Lake, in Utah; at Humbolt Lake, in Nevada; and at Honey Lake in eastern California. All these points lie within the Great Basin, and the beetle is entirely unknown from any other localities, though it has a close relative, Cicindela pseudosenilis, at Owens' Lake, also within the Basin. All these lakes are now separated by miles of burning desert, forming a barrier that completely prohibits intercourse between the different colonies. The breeding of the species on these deserts is equally impossible, since a certain amount of moisture, the year round, is necessary for its growth.

How are we to explain such a distribution? Why do we find colonies, idently arising from the same stock, though the members of one differ more cr less from those of another, scattered in these widely separated localities, when it is perfectly evident that conditions are such that passage from one lake to another is out of the question? My reply is, we must look to the ancient history of the region-to its geological record-for our answer.

Even the earliest explorers of the Great Basin noticed that the terraces on the mountains near Great Salt Lake indicated the former existence of a much larger body of water on the same site. The geologists of the United States Geological Survey have completed a study of the evidence, and have mapped the boundaries of the great lakes that are now known to have occuried the valleys during the Pleistocene periods. Their maps show the existence of two principal water bodies, one to the eastward, which has received the name Lake Bonneville, and one to the westward, known as Lake Lahontan. Between them was a plateau, dotted with smaller lakes.

With the passage of the ages, there came about a great diminution of the rainfall, and a consequent shrinkage of the great lakes of the Basin. Then came a period of humidity and a second rise of the waters, followed by a time of drought even more complete. The lakes, as a result, lost greatly in volume, bays became detached from the main bodies, forming separate independent lakes, each in its own restricted basin. Some of these, in their turn, dried up altogether, others persisted, though often, perhaps, only as small

pools, fed by perennial springs-a condition exemplified to-day on the Sevier and Humboldt flats. These are practically extinct as lakes, since they contain water only in the winter or after heavy floods, and the shore beetles have been forced to gather about the few small springs that moisten the ground along the borders.

My proposed explanation, correlating the briefly outlined geological histury with the facts offered as to the distribution of the insects, may be summarized as follows:

1. The shore beetles under consideration are confined to the Great Basin or its immediate borders, and have, in general, no allies in other districts from which they could have been recently developed. This in itself is strong presumptive evidence that they are endemic, not immigrants.

2. Within the Basin, recent conditions are such that the present distribution cannot possibly be a matter of modern origin. The small lakes now remaining in the Basin are separated by great tracts of arid desert, impassable to beetles depending on a moist soil for their development and food supply. The nature of these insects is such that they cannot be carried long distances, as eggs or larvæ, on the feet of birds or other animals.

3. Ancient conditions, as shown by the geological history through the Pleistocene, were favorable to the diffusion of shore-loving insects through the Basin, because of the much greater extension of the lakes in those times. 4. The insect most thoroughly studied, Cicindela echo, is entirely confined, in its present range, to the neighborhood of lakes, which from their size and the presence of nearby springs, may be presumed to have lasted in some form from a remote period-even through times of severe drought. Other littoral forms follow the same general law, though some of them are less sensitive to local conditions.

From these facts, I think we can come to but one conclusion-the beetles under consideration are types that have inhabited the Basin during the Pleistocene times when the shores of the great lakes stretched over hundreds of miles of what are now desert sands. As the lakes shrunk during times of drought, the insects followed the retreating beaches. Those which attached themselves to bodies of sufficient size or permanence were able to sustain their specific existence, while such as were dwelling on the edges of pools of a transient nature were exterminated altogether. Thus we have the phenomenon of discontinuous distribution, presented not by one species alone but by an entire assemblage.

The Chairman, Dr. Fletcher, expressed in happy terms the thanks of the audience to Prof. Wickham, for his interesting address and his kindness in travelling so far to attend the annual meeting of the Society.

SECOND DAY'S SESSION.

The Entomological Society resumed its meetings at 10.30 o'clock, a.m., the President, Prof. Lochhead, occupying the chair. The first order of business was the election of officers for the year 1904-5, which resulted as shewn on page two.

Dr. Fletcher moved, seconded by Mr. G. E. Fisher, "that popular articles should be published in the Canadian Entomologist next year, at least two pages per month, or more at the discretion of the Editor." After some remarks by the mover and seconder and also by the Editor in support of the resolution, it was unanimously adopted.

Dr. Fletcher moved, seconded by Mr. J.D. Evans, "that a special vote of thanks be given to the Library and Rooms Committee for the work they have undertaken and so successfully carried out in moving the Society's library, collections and other property into their new room."-Carried unanimously.

On motion of Dr. Bethune, seconded by Dr. Fletcher, DR WILLIAM H. ASHMEAD, of the United States National Museum at Washington, author of many works on Hymenoptera, and a regular contributor to the Canadian Entomologist, was elected an Honorary Member of the Society.

During the last forty years the Society has only elected 21 Honorary Members, of whom eleven are still living.

The next order of business was the reading of papers, which occupied the rest of the morning and the session in the afternoon; among those read were two, which have since been published in the Canadian Entomologist as they were of a somewhat technical character, viz.: "The systematic position of the Ægialitida" by Prof. Wickham and "Further notes on types in the British Museum," by Mr. Lyman. Both these papers were illustrated with

specimens of the insects referred to.

The following exhibits were shown by those attending the meeting: By Dr. James Fletcher: A box containing specimens of about twenty species of Canadian Xylinas, illustrating his remarks upon the genus; also Dimorpliopteryx pinguis and the Negundo Twig-borer Proteopteryx Willingana, two new and interesting species; Syngrapha ignea, Autographa flagellum, a co-type of Autographa rubidus, and Panchlora viridis taken at Winnipeg the first record in Canada.

By Mr. T. N. Willing: Several boxes of Lepidoptera, Coleoptera, etc., collected in the Northwest Territories.

By Mr. Arthur Gibson: A collection of about twenty inflated larvæ, and a box of lepidoptera bred at Ottawa, among which were specimens of Apantesis superba, Papaipema purpurifascia, etc. Also some American Beauty Roses from a conservatory in Toronto which were badly affected by a Thrips. It attacked the buds on the outside and thus spoiled the bloom. Fumigation with tobacco was found to control it satisfactorily.

By Mr. H. H. Lyman: A number of species of Gortyna (Hydrœcia), both moths and inflated larvæ, among which was a new species not yet described. Also some Lepidoptera collected in Italy and other European countries.

By Mr. C. H. Young:

A collection of Micro-Lepidoptera, containing about three hundred specimens of these exquisite moths, all most beautifully and perfectly mounted.

By Mr. J. D. Evans: A number of specimens collected at light in illustration of his paper.

By Mr. J. B. Williams: Specimens of Lepidoptera taken in the neighbourhood of Toronto.

By Prof. Wickham:

Dissected specimens of Egialites and allied genera, showing the structure of the under-side of the prothorax, in illustration of his paper.

By Mr. C. E. Grant: A box containing over seventy specimens of moths collected at Orillia.

By Mr. J. W. Cockle: A number of specimens of cocoons of Telea polyphemus shewing a great variety of spinning methods, in illustration of his

raper.

In connection with the exhibits, Dr. Fletcher read an extract from a letter recently received from Dr. Ottolengui of New York, which referred to certain species of Canadian Plusias. It was as follows:

Autographa rubidus, Ottol.

"I have retained the male of rubidus and send you one of my three females. It is in quite as good condition, and, as it was before me when I described the species, I find it has a co-type label on it. This I leave, and trust that the specimen may find its way into one of your society or national

museums.

The species is an interesting one to me as I think it accounts for the reported captures of iota to be found in Canadian literature. I have the true iota from Europe, from which it differs greatly, but it is not so dissimilar from the iota of some of the old published lithographic plates, and as the older writers used the European names for the American fauna rather more freely than we do now, I think rubidus is what they all called Iota. I have seen in all, only seven specimens of this, three of which I have. All came from eastern Canada except one determined for Mr. Wolley-Dod. This gives you the range, and it should be found anywhere in Canada.

You have two specimens of flagellum. This was long called monodon, until Prof. Smith discovered both types in the British Museum, and correctly announced in his Bulletin of the Noctuidæ, that both types referred to one species, thus giving flagellum antecedence. Nevertheless subsequently he renamed the species insolita, which of course falls. My specimens have been compared with all true types.

A word about fratella, a name which I notice in turning the pages of the Catalogue before me. I omitted this from my list, as a synoym of ou. Just before his death Mr. Grote sent a note to the Canadian Entomologist denying this synonomy. The same denial is to be found on the same authority in Smith's Catalogue; Morrison having declared fratella to be ou. By closely reading the paragraph referring to ou in the same work we find that though it is stated that the ou of the Grote collection agrees with Guenée's type in the British Museum, nevertheless we are told that Californica is a form of ou rather than of gamma. As a matter of fact, Californica is quite easily separated from ou, but is not so distinct from European gamma.

Sir George Hampson kindly made comparison of my material for me and selected a brilliantly marked large specimen as agreeing with the type of ou, and a very small dull colored specimen from Texas, he says "agrees with types of ou and fratella. Both identical." I should add that I sent all my material to Sir George Hampson without labels other than numbers, my labels being kept at home on pins similarly numbered. He was therefore not influenced by my views. As this comparison was made long after Mr. Grote had parted with his type, and as he gives no distinguishing characteristic in his description, by all rules fratella must pass into the synonomy.

Oxygramma is usually considered a southern species, but I already have it from London, Ontario, through Dr. Bethune.'

At the close of the meeting votes of thanks were unanimously adopted to Principal Merchant for his kindness in allowing the Society to use the Lecture-room at the Normal School, and the lantern for their public meeting in Wednesday night; to Mr. S. B. McCready, for so satisfactorily manipulating the lantern and slides; and to Prof. Wickham and Mr. Willing, for coming such long distances to read papers and take part in the proceedings of the annual meeting.